Adding a Connection to Apache Kafka

To add a connection to Apache Kafka:

1. In the application console, navigate to the Connections page.
2. At the Add Connections panel, select the icon for the connection you want to add.
3. If the Apache Kafka icon is not available, click the Add More icon to download and install the Apache Kafka connector from the CData site.

For required properties, see the Settings tab.

For connection properties that are not typically required, see the Advanced tab.

Connecting to Apache Kafka

.NET-based editions rely on the Confluent.Kafka and librdkafka libraries to function. These assemblies are bundled with the installer and automatically installed alongside the Sync App. If you are using a different installation method, make sure to install Confluent.Kafka 2.3.0 from NuGet along with its dependencies.

Set BootstrapServers to specify the address of your Apache Kafka server.

By default, the Sync App communicates with the data source in PLAINTEXT, which means that all data is sent in the clear. To encrypt communication, you should configure the Sync App to use SSL encryption. To do this, set UseSSL to true and configure SSLServerCert and SSLServerCertType to load the server certificates.

Note that proxy settings like ProxyServer and firewall settings like FirewallServer do not affect the connection to the Apache Kafka broker. Internally, the Sync App connects to Apache Kafka using the official libraries which do not support proxies. These options are only used when the Sync App connects to the schema registry as described in Extracting Metadata From Topics.

Authenticating to Apache Kafka

The Apache Kafka data source supports the following authentication methods:

• Anonymous
• Plain
• Scram
• Kerberos

Anonymous

Certain on-premise deployments of Apache Kafka are able to connect to Apache Kafka without setting any authentication connection properties. To do so, simply set the AuthScheme to "None", and you are ready to connect.

SASL Plain

The User and Password properties should be specified. AuthScheme should be set to Plain.

SCRAM login module

The User and Password properties should be specified. The AuthScheme should be set to 'SCRAM' (for SCRAM-SHA-256) or 'SCRAM-SHA-512'.

SSL client certificates

The SSLClientCert and SSLClientCertType properties should be specified and AuthScheme should be set to SSLCertificate.

Kerberos

To authenticate to Apache Kafka using Kerberos, set the following properties:

• AuthScheme: KERBEROS.
• KerberosServiceName: This should match the principal name of the Kafka brokers. For example, if the principal is kafka/[email protected], KerberosServiceName=kafka.

Connecting to Azure Event Hubs

The Sync App supports connecting to Azure Event Hubs using OAuth and shared-access signatures. Before you begin, check that your Event Hubs namespace supports connections using the Kafka protocol. The Sync App requires this feature and it may not be available for certain pricing tiers.

All connections to Azure must set these properties, in addition to the scheme-specific properties covered below.

• BootstrapServers: mynamespace.servicebus.windows.net:9093.
• UseSSL: True.

Azure AD

Azure AD is Microsoft’s multi-tenant, cloud-based directory and identity management service. It is user-based authentication that requires that you set AuthScheme to AzureAD.

OAuth

CData provides an embedded OAuth application that simplifies authentication. You can, however, create a custom application for authentication. For information about creating a custom application and reasons for doing so, see Creating a Custom OAuth Application.

For authentication, the only difference between using the CData-provided (embedded) application and creating your own custom application is that you must set two additional connection properties in the Advanced Tab when using custom OAuth applications.

Before you connect, for Custom Azure AD applications only, set the following variables:

• OAuthClientId: The client Id assigned when you registered your custom OAuth application.
• OAuthClientSecret: The client secret assigned when you registered your custom OAuth application.

Click Connect to Apache Kafka to open the OAuth endpoint in your default browser. Log in and grant permissions to the application.

The driver then completes the OAuth process as follows:

• Extracts the access token from the callback URL.
• Obtains a new access token when the old one expires.
• Saves OAuth values so that they persist across connections.

Azure Service Principal

Azure Service Principal is role-based application-based authentication. This means that authentication is done per application, rather than per user. All tasks taken on by the application are executed without a default user context, but based on the assigned roles. The application access to the resources is controlled through the assigned roles' permissions.

For information about how to set up Azure Service Principal authentication, see Creating a Custom OAuth Application.

Managed Service Identity (MSI)

If you are running Apache Kafka on an Azure VM and want to leverage MSI to connect, set AuthScheme to AzureMSI.

User-Managed Identities

To obtain a token for a managed identity, use the OAuthClientId property to specify the managed identity's "client_id".

When your VM has multiple user-assigned managed identities, you must also specify OAuthClientId.

Shared-Access Signature

The Sync App also supports password-based authentication using shared-access signatures. Once you have created a shared secret, configure the Sync App with these options:

• AuthScheme: Plain.
• User: $ConnectionString.
• Password: The Event Hubs connection string from the Shared Access Policies screen.

This section details a selection of advanced features of the Apache Kafka Sync App.

User Defined Views

The Sync App allows you to define virtual tables, called user defined views, whose contents are decided by a pre-configured query. These views are useful when you cannot directly control queries being issued to the drivers. See User Defined Views for an overview of creating and configuring custom views.

SSL Configuration

Use SSL Configuration to adjust how Sync App handles TLS/SSL certificate negotiations. You can choose from various certificate formats; see the SSLServerCert property under "Connection String Options" for more information.

Firewall and Proxy

Configure the Sync App for compliance with Firewall and Proxy, including Windows proxies and HTTP proxies. You can also set up tunnel connections.

Query Processing

The Sync App offloads as much of the SELECT statement processing as possible to Apache Kafka and then processes the rest of the query in memory (client-side).

See Query Processing for more information.

Logging

See Logging for an overview of configuration settings that can be used to refine CData logging. For basic logging, you only need to set two connection properties, but there are numerous features that support more refined logging, where you can select subsets of information to be logged using the LogModules connection property.

Customizing the SSL Configuration

By default, the Sync App attempts to negotiate SSL/TLS by checking the server's certificate against the system's trusted certificate store.

To specify another certificate, see the SSLServerCert property for the available formats to do so.

Client SSL Certificates

The Apache Kafka Sync App also supports setting client certificates. Set the following to connect using a client certificate.

• SSLClientCert: The name of the certificate store for the client certificate.
• SSLClientCertType: The type of key store containing the TLS/SSL client certificate.
• SSLClientCertPassword: The password for the TLS/SSL client certificate.
• SSLClientCertSubject: The subject of the TLS/SSL client certificate.

Connecting Through a Firewall or Proxy

HTTP Proxies

To connect through the Windows system proxy, you do not need to set any additional connection properties. To connect to other proxies, set ProxyAutoDetect to false.

In addition, to authenticate to an HTTP proxy, set ProxyAuthScheme, ProxyUser, and ProxyPassword, in addition to ProxyServer and ProxyPort.

Other Proxies

Set the following properties:

• To use a proxy-based firewall, set FirewallType, FirewallServer, and FirewallPort.
• To tunnel the connection, set FirewallType to TUNNEL.
• To authenticate, specify FirewallUser and FirewallPassword.
• To authenticate to a SOCKS proxy, additionally set FirewallType to SOCKS5.

Tables

The CData Sync App dynamically models Apache Kafka topics as tables. A complete list of discovered topics can be obtained from the sys_tables system table.

SELECTing from a topic returns existing messages on the topic, as well as live messages posted before the number of seconds specified by the ReadDuration have elapsed.

Stored Procedures

Stored Procedures are function-like interfaces to Apache Kafka. They can be used to create schema files, commit messages, and more.

Consumer Groups

Connections that the Sync App makes to Apache Kafka are always part of a consumer group. You can control the consumer group by setting a value for the ConsumerGroupId connection property. Using the same consumer group ID across multiple connections puts those connections into the same consumer group. The Sync App generates a random consumer group ID if one is not provided.

All members of a consumer group share an offset that determines what messages are read next within each topic and partition. The Sync App supports two ways of updating the offset:

• If AutoCommit is enabled, the Sync App periodically commits the offset for any topics and partitions that have been read by SELECT queries. The exact interval is determined by the auto-commit properties in the native library. See ConsumerProperties for details on how to configure these properties.
• The CommitOffset stored procedure stores the offset of the last item read by the current query. Note that this must be called while the query resultset is still open. The Sync App resets the offset when the resultset is closed.

If there is no existing offset, the Sync App uses the OffsetResetStrategy to determine what the offset should be. This may happen if the broker does not recognize the consumer group or if the consumer group never committed an offset.

Bulk Messages

The Sync App supports reading bulk messages from topics using the CSV, JSON, or XML SerializationFormat. For example, if a single message contained this CSV data, the Sync App would expand it into three rows:

"1","alpha"
"2","beta"
"3","gamma"

Apache Kafka does not natively support bulk messages, which can lead to rows being skipped in some circumstances. For example:

1. A Sync App connection is created with ConsumerGroupId=x
2. The connection executes the query SELECT * FROM topic LIMIT 3.
3. The connection commits its offset and closes.
4. Another connection is created with the same ConsumerGroupId
5. The connection executes the query SELECT * FROM topic.

Consider what happens if this procedure is performed on the following topic. The first connection consumes all rows from the first message and one row from the second. However, the Sync App has no way to report to Apache Kafka that only part of the second message was read. This means that step 3 commits the offset 3 and the second connection starts on row 5, skipping row 4.

"row 1"
"row 2"
/* End of message 1 */

"row 3"
"row 4"
/* End of message 2 */

"row 5"
"row 6"
/* End of message 3 */

The connection string properties are the various options that can be used to establish a connection. This section provides a complete list of the options you can configure in the connection string for this provider. Click the links for further details.

For more information on establishing a connection, see Establishing a Connection.

Authentication

---

Property	Description
AuthScheme	The scheme used for authentication with the Apache Kafka broker.
User	The user who is authenticating to Apache Kafka.
Password	The password used to authenticate to Apache Kafka.
BootstrapServers	The address of the Apache Kafka BootstrapServers to which you are connecting to.
Topic	The topic used for read and write operations.
UseSSL	This field sets whether SSL is enabled. Automatically enabled if AuthScheme is set to SSL.

Connection

---

Property	Description
ConsumerGroupId	Specifies which group the consumers created by the driver should belong to.
AutoCommit	Specifies if the Apache Kafka consumer should autocommit after each poll.

Azure Authentication

---

Property	Description
AzureTenant	The Microsoft Online tenant being used to access data. If not specified, your default tenant is used.
AzureResource	The Azure Active resource to authenticate to (used during Azure OAuth exchange).

OAuth

---

Property	Description
OAuthClientId	The client Id assigned when you register your application with an OAuth authorization server.
OAuthClientSecret	The client secret assigned when you register your application with an OAuth authorization server.

Kerberos

---

Property	Description
KerberosKeytabFile	The Keytab file containing your pairs of Kerberos principals and encrypted keys.
KerberosSPN	The service principal name (SPN) for the Kerberos Domain Controller.
KerberosServiceName	The name of the Kerberos service you want to authenticate with.
UseKerberosTicketCache	Set this to use a ticket cache with the logged in user instead of a keytab file.

SSL

---

Property	Description
SSLServerCert	The SSL server certificate used to validate to the Apache Kafka broker.
SSLServerCertType	The format of the SSL server certificate used to verify the Apache Kafka broker.
SSLClientCert	The SSL client certificate used to connect to the Apache Kafka broker.
SSLClientCertType	The format of the SSL client certificate used to connect to the Apache Kafka broker.
SSLClientCertPassword	The password used to decrypt the certificate in SSLClientCert .
SSLIdentificationAlgorithm	The endpoint identification algorithm used by the Apache Kafka data provider client app to validate server host name.

Schema Registry

---

Property	Description
RegistryUrl	The server for the schema registry. When this property is specified, the driver will read Apache Avro schema from the server.
RegistryType	Type of the schema specified for the a specific topic.
RegistryService	The Schema Registry service used for working with topic schemas.
RegistryAuthScheme	The scheme used to authenticate to the schema registry.
RegistryUser	Username to authorize with the server specified in RegistryUrl .
RegistryPassword	Password to authorize with the server specified in RegistryUrl .
RegistryClientCert	The TLS/SSL client certificate store for SSL Client Authentication (2-way SSL) with the schema registry.
RegistryClientCertType	The type of key store used by the TLS/SSL client certificate given in RegistryClientCert .
RegistryClientCertPassword	The password for the TLS/SSL client certificate given in RegistryClientCert .
RegistryClientCertSubject	The subject of the TLS/SSL client certificate given in RegistryClientCert .
RegistryVersion	Version of the schema read from RegistryUrl for the specified topic.
RegistryServerCert	The certificate to be accepted from the schema registry when connecting using TLS/SSL.

Firewall

---

Property	Description
FirewallType	The protocol used by a proxy-based firewall.
FirewallServer	The name or IP address of a proxy-based firewall.
FirewallPort	The TCP port for a proxy-based firewall.
FirewallUser	The user name to use to authenticate with a proxy-based firewall.
FirewallPassword	A password used to authenticate to a proxy-based firewall.

Proxy

---

Property	Description
ProxyAutoDetect	This indicates whether to use the system proxy settings or not.
ProxyServer	The hostname or IP address of a proxy to route HTTP traffic through.
ProxyPort	The TCP port the ProxyServer proxy is running on.
ProxyAuthScheme	The authentication type to use to authenticate to the ProxyServer proxy.
ProxyUser	A user name to be used to authenticate to the ProxyServer proxy.
ProxyPassword	A password to be used to authenticate to the ProxyServer proxy.
ProxySSLType	The SSL type to use when connecting to the ProxyServer proxy.
ProxyExceptions	A semicolon separated list of destination hostnames or IPs that are exempt from connecting through the ProxyServer .

Logging

---

Property	Description
LogModules	Core modules to be included in the log file.

Schema

---

Property	Description
Location	A path to the directory that contains the schema files defining tables, views, and stored procedures.
BrowsableSchemas	This property restricts the schemas reported to a subset of the available schemas. For example, BrowsableSchemas=SchemaA,SchemaB,SchemaC.
Tables	This property restricts the tables reported to a subset of the available tables. For example, Tables=TableA,TableB,TableC.
Views	Restricts the views reported to a subset of the available tables. For example, Views=ViewA,ViewB,ViewC.

Miscellaneous

---

Property	Description
AggregateMessages	Specifies whether or not to return the message as a whole string.
CompressionType	Data compression type. Batches of data will be compressed together.
ConsumerProperties	Additional options used to configure Kafka consumers.
CreateTablePartitions	The number of partitions assigned to a topic created with CREATE TABLE.
CreateTableReplicationFactor	The number of replicas assigned to a topic created with CREATE TABLE.
EnableIdempotence	If set to true, the Apache Kafka will ensure messages are delivered in the correct order, and without duplicates.
FlattenArrays	By default, nested arrays won't show up if TypeDetectionScheme is set to SchemaRegistry. The FlattenArrays property can be used to flatten the elements of nested arrays into columns of their own. Set FlattenArrays to the number of elements you want to return from nested arrays.
GenerateSchemaFiles	Indicates the user preference as to when schemas should be generated and saved.
MaximumBatchSize	Specifies maximum batch size to gather before sending a request.
MaxRows	Limits the number of rows returned when no aggregation or GROUP BY is used in the query. This takes precedence over LIMIT clauses.
MessageKeyColumn	If specified, the message key sent to Apache Kafka will be read from this column.
MessageKeyType	If MessageKeyColumn is specified, this property must be set to the expected type for the pertinent column.
OffsetResetStrategy	Specifies an offset for the consumer group.
Other	These hidden properties are used only in specific use cases.
Pagesize	The maximum number of rows to fetch from Kafka at one time.
ProduceMeta	Specifies whether or not to send a meta message while producing the outgoing message.
ProducerProperties	Additional options used to configure Kafka producers.
PseudoColumns	This property indicates whether or not to include pseudo columns as columns to the table.
ReadDuration	The duration which additional messages are allowed.
RowScanDepth	The maximum number of messages to scan for the columns available in the topic.
SerializationFormat	Specifies how to serialize/deserialize message contents.
Timeout	The value in seconds until the timeout error is thrown, canceling the operation.
TypeDetectionScheme	Comma-separated list of options specifying how the provider will scan the data to determine the fields and datatypes for the bucket.
UseConfluentAvroFormat	Specifies how Avro data should be formatted during an INSERT.
UserDefinedViews	A filepath pointing to the JSON configuration file containing your custom views.
ValidateRegistryTopics	Specifies whether or not to validate schema registry topics against the Apache Kafka broker. Only has an effect when TypeDetectionScheme =SchemaRegistry.

This section provides a complete list of the Authentication properties you can configure in the connection string for this provider.

---

Property	Description
AuthScheme	The scheme used for authentication with the Apache Kafka broker.
User	The user who is authenticating to Apache Kafka.
Password	The password used to authenticate to Apache Kafka.
BootstrapServers	The address of the Apache Kafka BootstrapServers to which you are connecting to.
Topic	The topic used for read and write operations.
UseSSL	This field sets whether SSL is enabled. Automatically enabled if AuthScheme is set to SSL.

The scheme used for authentication with the Apache Kafka broker.

Remarks

The supported schemes are described as follows:

Auto	Lets the Sync App decide automatically based on the other connection properties you have set.
None	Anonymous authentication will be used, and you can connect to the data source without specifying the user credentials.
Plain	The plain text login module will be used.
SCRAM	The SCRAM login module will be used with SHA-256 hashing.
SCRAM-SHA-512	The SCRAM login module will be used with SHA-512 hashing.
Kerberos	Kerberos authentication will be used, when using this value the system kerberos configuration file should be specified.
SSLCertificate	SSL client certificate authentication will be used.

In addition, the following schemes are supported when connecting to Azure Event Hubs:

AzureAD	Set this to perform Azure Active Directory OAuth authentication.
AzureMSI	Set this to automatically obtain Managed Service Identity credentials when running on an Azure VM.
AzureServicePrincipal	Set this to authenticate as an Azure Service Principal using a Client Secret.
AzureServicePrincipalCert	Set this to authenticate as an Azure Service Principal using a Certificate.

The user who is authenticating to Apache Kafka.

Remarks

If not specified, the driver will attempt unauthorized connection.

The password used to authenticate to Apache Kafka.

Remarks

If not specified, the driver will attempt an unauthorized connection.

The address of the Apache Kafka BootstrapServers to which you are connecting to.

Remarks

Specify both the server and port. The server may be either a hostname or IP address, for example: 10.1.2.3:9092. Multiple comma-separated addresses may be provided. As long as one of the bootstrap servers is in the list responses, the connection will be successful.

If you are connecting to Confluent Cloud, you can find this on the Cluster settings.

The topic used for read and write operations.

Remarks

By default the Sync App supports producing into and consuming from all topics in Kafka. You can limit it to just one topic by setting this option.

This field sets whether SSL is enabled. Automatically enabled if AuthScheme is set to SSL.

Remarks

This field sets whether the Sync App will attempt to negotiate TLS/SSL connections to the server. By default, the Sync App checks the server's certificate against the system's trusted certificate store. To specify another certificate, set SSLServerCert.

This section provides a complete list of the Connection properties you can configure in the connection string for this provider.

---

Property	Description
ConsumerGroupId	Specifies which group the consumers created by the driver should belong to.
AutoCommit	Specifies if the Apache Kafka consumer should autocommit after each poll.

Specifies which group the consumers created by the driver should belong to.

Remarks

If not specified, the driver will assign a random string.

Specifies if the Apache Kafka consumer should autocommit after each poll.

Remarks

If true, the consumer's offset will be periodically committed in the background.

This section provides a complete list of the Azure Authentication properties you can configure in the connection string for this provider.

---

Property	Description
AzureTenant	The Microsoft Online tenant being used to access data. If not specified, your default tenant is used.
AzureResource	The Azure Active resource to authenticate to (used during Azure OAuth exchange).

The Microsoft Online tenant being used to access data. If not specified, your default tenant is used.

Remarks

The Microsoft Online tenant being used to access data. For instance, contoso.onmicrosoft.com. Alternatively, specify the tenant Id. This value is the directory Id in the Azure Portal > Azure Active Directory > Properties.

Typically it is not necessary to specify the Tenant. This can be automatically determined by Microsoft when using the OAuthGrantType set to CODE (default). However, it may fail in the case that the user belongs to multiple tenants. For instance, if an Admin of domain A invites a user of domain B to be a guest user. The user will now belong to both tenants. It is a good practice to specify the Tenant, although in general things should normally work without having to specify it.

The AzureTenant is required when setting OAuthGrantType to CLIENT. When using client credentials, there is no user context. The credentials are taken from the context of the app itself. While Microsoft still allows client credentials to be obtained without specifying which Tenant, it has a much lower probability of picking the specific tenant you want to work with. For this reason, we require AzureTenant to be explicitly stated for all client credentials connections to ensure you get credentials that are applicable for the domain you intend to connect to.

The Microsoft Online tenant being used to access data. For instance, contoso.onmicrosoft.com. Alternatively, specify the tenant Id. This value is the directory Id in the Azure Portal > Azure Active Directory > Properties.

Typically it is not necessary to specify the Tenant. This can be automatically determined by Microsoft when using the OAuthGrantType set to CODE (default). However, it may fail in the case that the user belongs to multiple tenants. For instance, if an Admin of domain A invites a user of domain B to be a guest user. The user will now belong to both tenants. It is a good practice to specify the Tenant, although in general things should normally work without having to specify it.

The AzureTenant is required when setting OAuthGrantType to CLIENT. When using client credentials, there is no user context. The credentials are taken from the context of the app itself. While Microsoft still allows client credentials to be obtained without specifying which Tenant, it has a much lower probability of picking the specific tenant you want to work with. For this reason, we require AzureTenant to be explicitly stated for all client credentials connections to ensure you get credentials that are applicable for the domain you intend to connect to.

The Azure Active resource to authenticate to (used during Azure OAuth exchange).

Remarks

The resource must be specified if using Azure OAuth. It should be set to the App Id URI of the web API (secured resource).

This section provides a complete list of the OAuth properties you can configure in the connection string for this provider.

---

Property	Description
OAuthClientId	The client Id assigned when you register your application with an OAuth authorization server.
OAuthClientSecret	The client secret assigned when you register your application with an OAuth authorization server.

The client Id assigned when you register your application with an OAuth authorization server.

Remarks

As part of registering an OAuth application, you will receive the OAuthClientId value, sometimes also called a consumer key, and a client secret, the OAuthClientSecret.

The client secret assigned when you register your application with an OAuth authorization server.

Remarks

As part of registering an OAuth application, you will receive the OAuthClientId, also called a consumer key. You will also receive a client secret, also called a consumer secret. Set the client secret in the OAuthClientSecret property.

This section provides a complete list of the Kerberos properties you can configure in the connection string for this provider.

---

Property	Description
KerberosKeytabFile	The Keytab file containing your pairs of Kerberos principals and encrypted keys.
KerberosSPN	The service principal name (SPN) for the Kerberos Domain Controller.
KerberosServiceName	The name of the Kerberos service you want to authenticate with.
UseKerberosTicketCache	Set this to use a ticket cache with the logged in user instead of a keytab file.

The Keytab file containing your pairs of Kerberos principals and encrypted keys.

Remarks

The Keytab file containing your pairs of Kerberos principals and encrypted keys.

The service principal name (SPN) for the Kerberos Domain Controller.

Remarks

The service principal name (SPN) for the Kerberos Domain Controller.

The name of the Kerberos service you want to authenticate with.

Remarks

The name of the Kerberos service you want to authenticate with.

Set this to use a ticket cache with the logged in user instead of a keytab file.

Remarks

Set this to use a ticket cache with the logged in user instead of a keytab file

This section provides a complete list of the SSL properties you can configure in the connection string for this provider.

---

Property	Description
SSLServerCert	The SSL server certificate used to validate to the Apache Kafka broker.
SSLServerCertType	The format of the SSL server certificate used to verify the Apache Kafka broker.
SSLClientCert	The SSL client certificate used to connect to the Apache Kafka broker.
SSLClientCertType	The format of the SSL client certificate used to connect to the Apache Kafka broker.
SSLClientCertPassword	The password used to decrypt the certificate in SSLClientCert .
SSLIdentificationAlgorithm	The endpoint identification algorithm used by the Apache Kafka data provider client app to validate server host name.

The SSL server certificate used to validate to the Apache Kafka broker.

Remarks

The value of this property must be provided in the format described on the SSLServerCertType page. Please refer to it for more details.

The format of the SSL server certificate used to verify the Apache Kafka broker.

Remarks

This property is used to determine what format the SSLServerCert property expects. This property can take one of the following values:

PEMKEY_FILE	The certificate store is the name of a PEM-encoded file that contains a the server certificate.
PEMKEY_BLOB	The certificate store is a string that contains the server certificate.

The SSL client certificate used to connect to the Apache Kafka broker.

Remarks

The value of this property must be provided in the format described on the SSLClientCertType page. Please refer to it for more details.

The format of the SSL client certificate used to connect to the Apache Kafka broker.

Remarks

This property is used to determine what format the SSLClientCert property expects. This property can take one of the following values:

PEMKEY_FILE	The certificate store is the name of a PEM-encoded file that contains a private key and certificate.
PEMKEY_BLOB	The certificate store is a string that contains a private key and certificate, optionally encoded in base64.

The password used to decrypt the certificate in SSLClientCert .

Remarks

Leave this blank if the client certificate isn't password protected.

The endpoint identification algorithm used by the Apache Kafka data provider client app to validate server host name.

Remarks

The default value is 'https' and the server host name validation is enabled. You can disable it by setting its value to a blank space.

This section provides a complete list of the Schema Registry properties you can configure in the connection string for this provider.

---

Property	Description
RegistryUrl	The server for the schema registry. When this property is specified, the driver will read Apache Avro schema from the server.
RegistryType	Type of the schema specified for the a specific topic.
RegistryService	The Schema Registry service used for working with topic schemas.
RegistryAuthScheme	The scheme used to authenticate to the schema registry.
RegistryUser	Username to authorize with the server specified in RegistryUrl .
RegistryPassword	Password to authorize with the server specified in RegistryUrl .
RegistryClientCert	The TLS/SSL client certificate store for SSL Client Authentication (2-way SSL) with the schema registry.
RegistryClientCertType	The type of key store used by the TLS/SSL client certificate given in RegistryClientCert .
RegistryClientCertPassword	The password for the TLS/SSL client certificate given in RegistryClientCert .
RegistryClientCertSubject	The subject of the TLS/SSL client certificate given in RegistryClientCert .
RegistryVersion	Version of the schema read from RegistryUrl for the specified topic.
RegistryServerCert	The certificate to be accepted from the schema registry when connecting using TLS/SSL.

The server for the schema registry. When this property is specified, the driver will read Apache Avro schema from the server.

Remarks

Note this property provides no additional features when SerializationFormat is not set to Avro.

• If you are connecting to Confluent Cloud, this corresponds to the Schema Registry endpoint value in Schemas > Schema Registry > Instructions.
• If you are connecting to AWS Glue service, this corresponds to the ARN value of the AWS Registry you want to connect.

Type of the schema specified for the a specific topic.

Remarks

Currently we do not support Protobuf. If this value is set to Auto, then we driver will try to detect the valid Schema Registry Type for the selected Topic.

The Schema Registry service used for working with topic schemas.

Remarks

The Schema Registry service used for working with topic schemas.

The scheme used to authenticate to the schema registry.

Remarks

The schemes are as follows. Note that some schemes are only available when connecting to a specific RegistryService:

Auto	Lets the Sync App decide automatically based on the other connection properties you have set.
None	No authentication will be used.
Basic	RegistryUser and RegistryPassword are used. In Confluent these are the API user/password, while in Glue these are the IAM access key/secret key.
SSLCertificate	RegistryClientCert is used with SSL client authentication. This is only supported when connecting to a Confluent registry.

Username to authorize with the server specified in RegistryUrl .

Remarks

If you are connecting to Confluent Cloud, this corresponds to the Access Key value in Schemas > Schema Registry > API access.

Password to authorize with the server specified in RegistryUrl .

Remarks

If you are connecting to Confluent Cloud, this corresponds to the Secret Key value in Schemas > Schema Registry > API access.

The TLS/SSL client certificate store for SSL Client Authentication (2-way SSL) with the schema registry.

Remarks

The name of the certificate store for the client certificate.

The RegistryClientCertType field specifies the type of the certificate store specified by RegistryClientCert. If the store is password protected, specify the password in RegistryClientCertPassword.

RegistryClientCert is used in conjunction with the RegistryClientCertSubject field in order to specify client certificates. If RegistryClientCert has a value, and RegistryClientCertSubject is set, a search for a certificate is initiated. See RegistryClientCertSubject for more information.

Designations of certificate stores are platform-dependent.

The following are designations of the most common User and Machine certificate stores in Windows:

MY	A certificate store holding personal certificates with their associated private keys.
CA	Certifying authority certificates.
ROOT	Root certificates.
SPC	Software publisher certificates.

In Java, the certificate store normally is a file containing certificates and optional private keys.

When the certificate store type is PFXFile, this property must be set to the name of the file. When the type is PFXBlob, the property must be set to the binary contents of a PFX file (for example, PKCS12 certificate store).

The type of key store used by the TLS/SSL client certificate given in RegistryClientCert .

Remarks

This property can take one of the following values:

USER - default	For Windows, this specifies that the certificate store is a certificate store owned by the current user. Note that this store type is not available in Java.
MACHINE	For Windows, this specifies that the certificate store is a machine store. Note that this store type is not available in Java.
PFXFILE	The certificate store is the name of a PFX (PKCS12) file containing certificates.
PFXBLOB	The certificate store is a string (base-64-encoded) representing a certificate store in PFX (PKCS12) format.
JKSFILE	The certificate store is the name of a Java key store (JKS) file containing certificates. Note that this store type is only available in Java.
JKSBLOB	The certificate store is a string (base-64-encoded) representing a certificate store in JKS format. Note that this store type is only available in Java.
PEMKEY_FILE	The certificate store is the name of a PEM-encoded file that contains a private key and an optional certificate.
PEMKEY_BLOB	The certificate store is a string (base64-encoded) that contains a private key and an optional certificate.
PUBLIC_KEY_FILE	The certificate store is the name of a file that contains a PEM- or DER-encoded public key certificate.
PUBLIC_KEY_BLOB	The certificate store is a string (base-64-encoded) that contains a PEM- or DER-encoded public key certificate.
SSHPUBLIC_KEY_FILE	The certificate store is the name of a file that contains an SSH-style public key.
SSHPUBLIC_KEY_BLOB	The certificate store is a string (base-64-encoded) that contains an SSH-style public key.
P7BFILE	The certificate store is the name of a PKCS7 file containing certificates.
PPKFILE	The certificate store is the name of a file that contains a PuTTY Private Key (PPK).
XMLFILE	The certificate store is the name of a file that contains a certificate in XML format.
XMLBLOB	The certificate store is a string that contains a certificate in XML format.

The password for the TLS/SSL client certificate given in RegistryClientCert .

Remarks

If the certificate store is of a type that requires a password, this property is used to specify that password to open the certificate store.

The subject of the TLS/SSL client certificate given in RegistryClientCert .

Remarks

When loading a certificate the subject is used to locate the certificate in the store.

If an exact match is not found, the store is searched for subjects containing the value of the property. If a match is still not found, the property is set to an empty string, and no certificate is selected.

The special value "*" picks the first certificate in the certificate store.

The certificate subject is a comma separated list of distinguished name fields and values. For example, "CN=www.server.com, OU=test, C=US, [email protected]". The common fields and their meanings are shown below.

Field	Meaning
CN	Common Name. This is commonly a host name like www.server.com.
O	Organization
OU	Organizational Unit
L	Locality
S	State
C	Country
E	Email Address

If a field value contains a comma, it must be quoted.

Version of the schema read from RegistryUrl for the specified topic.

Remarks

Version of the schema read from RegistryUrl for the specified topic.

The certificate to be accepted from the schema registry when connecting using TLS/SSL.

Remarks

If using a TLS/SSL connection, this property can be used to specify the TLS/SSL certificate to be accepted from the server. Any other certificate that is not trusted by the machine is rejected.

This property can take the following forms:

Description	Example
A full PEM Certificate (example shortened for brevity)	-----BEGIN CERTIFICATE----- MIIChTCCAe4CAQAwDQYJKoZIhv......Qw== -----END CERTIFICATE-----
A path to a local file containing the certificate	C:\cert.cer
The public key (example shortened for brevity)	-----BEGIN RSA PUBLIC KEY----- MIGfMA0GCSq......AQAB -----END RSA PUBLIC KEY-----
The MD5 Thumbprint (hex values can also be either space or colon separated)	ecadbdda5a1529c58a1e9e09828d70e4
The SHA1 Thumbprint (hex values can also be either space or colon separated)	34a929226ae0819f2ec14b4a3d904f801cbb150d

If not specified, any certificate trusted by the machine is accepted.

Use '*' to signify to accept all certificates. Note that this is not recommended due to security concerns.

This section provides a complete list of the Firewall properties you can configure in the connection string for this provider.

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Property	Description
FirewallType	The protocol used by a proxy-based firewall.
FirewallServer	The name or IP address of a proxy-based firewall.
FirewallPort	The TCP port for a proxy-based firewall.
FirewallUser	The user name to use to authenticate with a proxy-based firewall.
FirewallPassword	A password used to authenticate to a proxy-based firewall.

The protocol used by a proxy-based firewall.

Remarks

This property specifies the protocol that the Sync App will use to tunnel traffic through the FirewallServer proxy. Note that by default, the Sync App connects to the system proxy; to disable this behavior and connect to one of the following proxy types, set ProxyAutoDetect to false.

Type	Default Port	Description
TUNNEL	80	When this is set, the Sync App opens a connection to Apache Kafka and traffic flows back and forth through the proxy.
SOCKS4	1080	When this is set, the Sync App sends data through the SOCKS 4 proxy specified by FirewallServer and FirewallPort and passes the FirewallUser value to the proxy, which determines if the connection request should be granted.
SOCKS5	1080	When this is set, the Sync App sends data through the SOCKS 5 proxy specified by FirewallServer and FirewallPort. If your proxy requires authentication, set FirewallUser and FirewallPassword to credentials the proxy recognizes.

To connect to HTTP proxies, use ProxyServer and ProxyPort. To authenticate to HTTP proxies, use ProxyAuthScheme, ProxyUser, and ProxyPassword.

The name or IP address of a proxy-based firewall.

Remarks

This property specifies the IP address, DNS name, or host name of a proxy allowing traversal of a firewall. The protocol is specified by FirewallType: Use FirewallServer with this property to connect through SOCKS or do tunneling. Use ProxyServer to connect to an HTTP proxy.

Note that the Sync App uses the system proxy by default. To use a different proxy, set ProxyAutoDetect to false.

The TCP port for a proxy-based firewall.

Remarks

This specifies the TCP port for a proxy allowing traversal of a firewall. Use FirewallServer to specify the name or IP address. Specify the protocol with FirewallType.

The user name to use to authenticate with a proxy-based firewall.

Remarks

The FirewallUser and FirewallPassword properties are used to authenticate against the proxy specified in FirewallServer and FirewallPort, following the authentication method specified in FirewallType.

A password used to authenticate to a proxy-based firewall.

Remarks

This property is passed to the proxy specified by FirewallServer and FirewallPort, following the authentication method specified by FirewallType.

This section provides a complete list of the Proxy properties you can configure in the connection string for this provider.

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Property	Description
ProxyAutoDetect	This indicates whether to use the system proxy settings or not.
ProxyServer	The hostname or IP address of a proxy to route HTTP traffic through.
ProxyPort	The TCP port the ProxyServer proxy is running on.
ProxyAuthScheme	The authentication type to use to authenticate to the ProxyServer proxy.
ProxyUser	A user name to be used to authenticate to the ProxyServer proxy.
ProxyPassword	A password to be used to authenticate to the ProxyServer proxy.
ProxySSLType	The SSL type to use when connecting to the ProxyServer proxy.
ProxyExceptions	A semicolon separated list of destination hostnames or IPs that are exempt from connecting through the ProxyServer .

This indicates whether to use the system proxy settings or not.

Remarks

This takes precedence over other proxy settings, so you'll need to set ProxyAutoDetect to FALSE in order use custom proxy settings.

To connect to an HTTP proxy, see ProxyServer. For other proxies, such as SOCKS or tunneling, see FirewallType.

The hostname or IP address of a proxy to route HTTP traffic through.

Remarks

The hostname or IP address of a proxy to route HTTP traffic through. The Sync App can use the HTTP, Windows (NTLM), or Kerberos authentication types to authenticate to an HTTP proxy.

If you need to connect through a SOCKS proxy or tunnel the connection, see FirewallType.

By default, the Sync App uses the system proxy. If you need to use another proxy, set ProxyAutoDetect to false.

The TCP port the ProxyServer proxy is running on.

Remarks

The port the HTTP proxy is running on that you want to redirect HTTP traffic through. Specify the HTTP proxy in ProxyServer. For other proxy types, see FirewallType.

The authentication type to use to authenticate to the ProxyServer proxy.

Remarks

This value specifies the authentication type to use to authenticate to the HTTP proxy specified by ProxyServer and ProxyPort.

Note that the Sync App will use the system proxy settings by default, without further configuration needed; if you want to connect to another proxy, you will need to set ProxyAutoDetect to false, in addition to ProxyServer and ProxyPort. To authenticate, set ProxyAuthScheme and set ProxyUser and ProxyPassword, if needed.

The authentication type can be one of the following:

• BASIC: The Sync App performs HTTP BASIC authentication.
• DIGEST: The Sync App performs HTTP DIGEST authentication.
• NEGOTIATE: The Sync App retrieves an NTLM or Kerberos token based on the applicable protocol for authentication.
• PROPRIETARY: The Sync App does not generate an NTLM or Kerberos token. You must supply this token in the Authorization header of the HTTP request.

If you need to use another authentication type, such as SOCKS 5 authentication, see FirewallType.

A user name to be used to authenticate to the ProxyServer proxy.

Remarks

The ProxyUser and ProxyPassword options are used to connect and authenticate against the HTTP proxy specified in ProxyServer.

You can select one of the available authentication types in ProxyAuthScheme. If you are using HTTP authentication, set this to the user name of a user recognized by the HTTP proxy. If you are using Windows or Kerberos authentication, set this property to a user name in one of the following formats:

user@domain
domain\user

A password to be used to authenticate to the ProxyServer proxy.

Remarks

This property is used to authenticate to an HTTP proxy server that supports NTLM (Windows), Kerberos, or HTTP authentication. To specify the HTTP proxy, you can set ProxyServer and ProxyPort. To specify the authentication type, set ProxyAuthScheme.

If you are using HTTP authentication, additionally set ProxyUser and ProxyPassword to HTTP proxy.

If you are using NTLM authentication, set ProxyUser and ProxyPassword to your Windows password. You may also need these to complete Kerberos authentication.

For SOCKS 5 authentication or tunneling, see FirewallType.

By default, the Sync App uses the system proxy. If you want to connect to another proxy, set ProxyAutoDetect to false.

The SSL type to use when connecting to the ProxyServer proxy.

Remarks

This property determines when to use SSL for the connection to an HTTP proxy specified by ProxyServer. This value can be AUTO, ALWAYS, NEVER, or TUNNEL. The applicable values are the following:

AUTO	Default setting. If the URL is an HTTPS URL, the Sync App will use the TUNNEL option. If the URL is an HTTP URL, the component will use the NEVER option.
ALWAYS	The connection is always SSL enabled.
NEVER	The connection is not SSL enabled.
TUNNEL	The connection is through a tunneling proxy. The proxy server opens a connection to the remote host and traffic flows back and forth through the proxy.

A semicolon separated list of destination hostnames or IPs that are exempt from connecting through the ProxyServer .

Remarks

The ProxyServer is used for all addresses, except for addresses defined in this property. Use semicolons to separate entries.

Note that the Sync App uses the system proxy settings by default, without further configuration needed; if you want to explicitly configure proxy exceptions for this connection, you need to set ProxyAutoDetect = false, and configure ProxyServer and ProxyPort. To authenticate, set ProxyAuthScheme and set ProxyUser and ProxyPassword, if needed.

This section provides a complete list of the Logging properties you can configure in the connection string for this provider.

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Property	Description
LogModules	Core modules to be included in the log file.

Core modules to be included in the log file.

Remarks

Only the modules specified (separated by ';') will be included in the log file. By default all modules are included.

See the Logging page for an overview.

This section provides a complete list of the Schema properties you can configure in the connection string for this provider.

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Property	Description
Location	A path to the directory that contains the schema files defining tables, views, and stored procedures.
BrowsableSchemas	This property restricts the schemas reported to a subset of the available schemas. For example, BrowsableSchemas=SchemaA,SchemaB,SchemaC.
Tables	This property restricts the tables reported to a subset of the available tables. For example, Tables=TableA,TableB,TableC.
Views	Restricts the views reported to a subset of the available tables. For example, Views=ViewA,ViewB,ViewC.

A path to the directory that contains the schema files defining tables, views, and stored procedures.

Remarks

The path to a directory which contains the schema files for the Sync App (.rsd files for tables and views, .rsb files for stored procedures). The folder location can be a relative path from the location of the executable. The Location property is only needed if you want to customize definitions (for example, change a column name, ignore a column, and so on) or extend the data model with new tables, views, or stored procedures.

If left unspecified, the default location is "%APPDATA%\\CData\\ApacheKafka Data Provider\\Schema" with %APPDATA% being set to the user's configuration directory:

Platform	%APPDATA%
Windows	The value of the APPDATA environment variable
Linux	~/.config

This property restricts the schemas reported to a subset of the available schemas. For example, BrowsableSchemas=SchemaA,SchemaB,SchemaC.

Remarks

Listing the schemas from databases can be expensive. Providing a list of schemas in the connection string improves the performance.

This property restricts the tables reported to a subset of the available tables. For example, Tables=TableA,TableB,TableC.

Remarks

Listing the tables from some databases can be expensive. Providing a list of tables in the connection string improves the performance of the Sync App.

This property can also be used as an alternative to automatically listing views if you already know which ones you want to work with and there would otherwise be too many to work with.

Specify the tables you want in a comma-separated list. Each table should be a valid SQL identifier with any special characters escaped using square brackets, double-quotes or backticks. For example, Tables=TableA,[TableB/WithSlash],WithCatalog.WithSchema.`TableC With Space`.

Note that when connecting to a data source with multiple schemas or catalogs, you will need to provide the fully qualified name of the table in this property, as in the last example here, to avoid ambiguity between tables that exist in multiple catalogs or schemas.

Restricts the views reported to a subset of the available tables. For example, Views=ViewA,ViewB,ViewC.

Remarks

Listing the views from some databases can be expensive. Providing a list of views in the connection string improves the performance of the Sync App.

This property can also be used as an alternative to automatically listing views if you already know which ones you want to work with and there would otherwise be too many to work with.

Specify the views you want in a comma-separated list. Each view should be a valid SQL identifier with any special characters escaped using square brackets, double-quotes or backticks. For example, Views=ViewA,[ViewB/WithSlash],WithCatalog.WithSchema.`ViewC With Space`.

Note that when connecting to a data source with multiple schemas or catalogs, you will need to provide the fully qualified name of the table in this property, as in the last example here, to avoid ambiguity between tables that exist in multiple catalogs or schemas.

This section provides a complete list of the Miscellaneous properties you can configure in the connection string for this provider.

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Property	Description
AggregateMessages	Specifies whether or not to return the message as a whole string.
CompressionType	Data compression type. Batches of data will be compressed together.
ConsumerProperties	Additional options used to configure Kafka consumers.
CreateTablePartitions	The number of partitions assigned to a topic created with CREATE TABLE.
CreateTableReplicationFactor	The number of replicas assigned to a topic created with CREATE TABLE.
EnableIdempotence	If set to true, the Apache Kafka will ensure messages are delivered in the correct order, and without duplicates.
FlattenArrays	By default, nested arrays won't show up if TypeDetectionScheme is set to SchemaRegistry. The FlattenArrays property can be used to flatten the elements of nested arrays into columns of their own. Set FlattenArrays to the number of elements you want to return from nested arrays.
GenerateSchemaFiles	Indicates the user preference as to when schemas should be generated and saved.
MaximumBatchSize	Specifies maximum batch size to gather before sending a request.
MaxRows	Limits the number of rows returned when no aggregation or GROUP BY is used in the query. This takes precedence over LIMIT clauses.
MessageKeyColumn	If specified, the message key sent to Apache Kafka will be read from this column.
MessageKeyType	If MessageKeyColumn is specified, this property must be set to the expected type for the pertinent column.
OffsetResetStrategy	Specifies an offset for the consumer group.
Other	These hidden properties are used only in specific use cases.
Pagesize	The maximum number of rows to fetch from Kafka at one time.
ProduceMeta	Specifies whether or not to send a meta message while producing the outgoing message.
ProducerProperties	Additional options used to configure Kafka producers.
PseudoColumns	This property indicates whether or not to include pseudo columns as columns to the table.
ReadDuration	The duration which additional messages are allowed.
RowScanDepth	The maximum number of messages to scan for the columns available in the topic.
SerializationFormat	Specifies how to serialize/deserialize message contents.
Timeout	The value in seconds until the timeout error is thrown, canceling the operation.
TypeDetectionScheme	Comma-separated list of options specifying how the provider will scan the data to determine the fields and datatypes for the bucket.
UseConfluentAvroFormat	Specifies how Avro data should be formatted during an INSERT.
UserDefinedViews	A filepath pointing to the JSON configuration file containing your custom views.
ValidateRegistryTopics	Specifies whether or not to validate schema registry topics against the Apache Kafka broker. Only has an effect when TypeDetectionScheme =SchemaRegistry.

Specifies whether or not to return the message as a whole string.

Remarks

When set to false, the result will be parsed and detected fields will appear in the resultset.

Data compression type. Batches of data will be compressed together.

Remarks

The following values are supported:

NONE	Messages will not be compressed.
GZIP	Messages will be compressed using gzip.
SNAPPY	Messages will be compressed using snappy.
LZ4	Messages will be compressed using lz4.

Additional options used to configure Kafka consumers.

Remarks

The Sync App exposes several Kafka consumer configuration values directly as connection properties. Internally, these are all mapped into properties that are passed to the Kafka client libraries.

If the Sync App does not expose an option for the consumer configuration, it can be set here. This option takes a connection string value and passes all its options directly to the consumer. For example, security.protocol=SASL_SSL;sasl.mechanism=SCRAM-SHA-512 sets the security.protocol and sasl.mechanism consumer properties.

The number of partitions assigned to a topic created with CREATE TABLE.

Remarks

When executing a CREATE TABLE statement, the Sync App creates a new empty topic. By default, the Sync App creates this new topic with 1 partition.

You can create topics with more partitions by changing this setting. This can be useful if you plan on having multiple consumers process the messages on this topic.

The number of replicas assigned to a topic created with CREATE TABLE.

Remarks

When executing a CREATE TABLE statement, the Sync App creates a new empty topic. By default, the Sync App creates this topic with a replication factor of 3.

You can create topics with a different number of replicas by changing this setting. There are two main cases where this is useful:

• When your cluster has fewer than 3 nodes. This setting should never be higher than the number of nodes in your cluster. For example, creating topics with a replication factor of 3 on a cluster with 2 nodes will fail.
• When your cluster has more than 3 nodes and you want more safety in case of failover. Apache Kafka uses replicas to prevent data loss when a node fails, and if all the replicas fail then the topic is unavailable.

If set to true, the Apache Kafka will ensure messages are delivered in the correct order, and without duplicates.

Remarks

Gives each message a sequence number when enabled. Specifies how to serialize/deserialize the incoming or outgoing message.

By default, nested arrays won't show up if TypeDetectionScheme is set to SchemaRegistry. The FlattenArrays property can be used to flatten the elements of nested arrays into columns of their own. Set FlattenArrays to the number of elements you want to return from nested arrays.

Remarks

Set FlattenArrays to the number of elements you want to return from nested arrays. The specified elements are returned as columns.

For example, you can return an arbitrary number of elements from an array of strings:

["FLOW-MATIC","LISP","COBOL"]

When FlattenArrays is set to 1, the preceding array is flattened into the following table:

Column Name	Column Value
languages.0	FLOW-MATIC

Indicates the user preference as to when schemas should be generated and saved.

Remarks

This property outputs schemas to .rsd files in the path specified by Location.

Available settings are the following:

• Never: A schema file will never be generated.
• OnUse: A schema file will be generated the first time a table is referenced, provided the schema file for the table does not already exist.
• OnStart: A schema file will be generated at connection time for any tables that do not currently have a schema file.
• OnCreate: A schema file will be generated by when running a CREATE TABLE SQL query.

Note that if you want to regenerate a file, you will first need to delete it.

Generate Schemas with SQL

When you set GenerateSchemaFiles to OnUse, the Sync App generates schemas as you execute SELECT queries. Schemas are generated for each table referenced in the query.

When you set GenerateSchemaFiles to OnCreate, schemas are only generated when a CREATE TABLE query is executed.

Generate Schemas on Connection

Another way to use this property is to obtain schemas for every table in your database when you connect. To do so, set GenerateSchemaFiles to OnStart and connect.

Specifies maximum batch size to gather before sending a request.

Remarks

A batch can be formed by one or more messages. The size is specified in bytes.

Limits the number of rows returned when no aggregation or GROUP BY is used in the query. This takes precedence over LIMIT clauses.

Remarks

Limits the number of rows returned when no aggregation or GROUP BY is used in the query. This takes precedence over LIMIT clauses.

If specified, the message key sent to Apache Kafka will be read from this column.

Remarks

If specified, the message key sent to Apache Kafka will be read from this column.

If MessageKeyColumn is specified, this property must be set to the expected type for the pertinent column.

Remarks

Be advised that, when this value is set to null, MessageKeyColumn will be ignored.

The available types are as follows:

Null	The key column type will be treated as null.
Binary	The key column type will be treated as a binary. The value will be reported in base64.
String	The key column type will be treated as a string.
Long	The key column type will be treated as a long.
Integer	The key column type will be treated as an integer.

Specifies an offset for the consumer group.

Remarks

Select one of the following strategies:

Latest	Will only consume messages that are produced after the consumer group is created.
Earliest	Will consume any unconsumed messages including any message produced before the lifetime of the consumer group.

These hidden properties are used only in specific use cases.

Remarks

The properties listed below are available for specific use cases. Normal driver use cases and functionality should not require these properties.

Specify multiple properties in a semicolon-separated list.

Integration and Formatting

DefaultColumnSize	Sets the default length of string fields when the data source does not provide column length in the metadata. The default value is 2000.
ConvertDateTimeToGMT	Determines whether to convert date-time values to GMT, instead of the local time of the machine.
RecordToFile=filename	Records the underlying socket data transfer to the specified file.

The maximum number of rows to fetch from Kafka at one time.

Remarks

The Sync App batches reads to Kafka to reduce overhead. Instead of fetching a single row from the broker every time a query row is read, the Sync App will read multiple rows and save them to the resultset. This means that only the first row read from the resultset must wait for the broker. Later rows can be read out of this buffer directly.

This option controls the maximum number of rows the Sync App stores on the resultset. Setting this to a higher value will use more memory but requires waiting on the broker less often. Lower values will give lower throughput while using less memory.

Specifies whether or not to send a meta message while producing the outgoing message.

Remarks

This option is only used if SerializationFormat is set to CSV.

Additional options used to configure Kafka producers.

Remarks

This option is like ConsumerProperties but applies to producers instead. Please refer to that property for more information.

This property indicates whether or not to include pseudo columns as columns to the table.

Remarks

This setting is particularly helpful in Entity Framework, which does not allow you to set a value for a pseudo column unless it is a table column. The value of this connection setting is of the format "Table1=Column1, Table1=Column2, Table2=Column3". You can use the "*" character to include all tables and all columns; for example, "*=*".

The duration which additional messages are allowed.

Remarks

A timeout for the Sync App to stop waiting for additional messages to come.

The maximum number of messages to scan for the columns available in the topic.

Remarks

Setting a high value may decrease performance. Setting a low value may prevent the data type from being determined properly.

Specifies how to serialize/deserialize message contents.

Remarks

The Sync App uses this property differently based on the value of TypeDetectionScheme:

• None, RowScan: The Sync App samples messages from the topic to determine their columns. If SerializationFormat is AUTO, then the format is determined based on the message content. Otherwise, the format is just the value of this property.
• SchemaRegistry: The Sync App uses SerializationFormat, a fallback, if it cannot determine the format from the registry. This is rare as it only happens when the registry does not specify a format and the schema cannot be inferred to be a JSON or Avro schema.
• MessageOnly: SerializationFormat determines how the message column is surfaced. If the format is AUTO, AVRO, or NONE, the message column is treated as binary and uses base64 encoded values. Otherwise, the message column is treated as text.

Available formats:

NONE	Message will be always BASE64 encoded on both the consume and produce operations.
AUTO	Attempt to automatically figure out the current topic's serialization format.
JSON	Message will be serialized using the JSON format.
CSV	Message will be serialized using the CSV format.
XML	Message will be serialized using the XML format.
AVRO	Message will be serialized using the Avro format.

The value in seconds until the timeout error is thrown, canceling the operation.

Remarks

If Timeout = 0, operations do not time out. The operations run until they complete successfully or until they encounter an error condition.

If Timeout expires and the operation is not yet complete, the Sync App throws an exception.

Comma-separated list of options specifying how the provider will scan the data to determine the fields and datatypes for the bucket.

Remarks

The type dection schemes are:

None	Setting TypeDetectionScheme to None will return all columns as string type.
RowScan	Setting TypeDetectionScheme to RowScan will scan rows to heuristically determine the data type. The RowScanDepth determines the number of rows to be scanned. Can be used with RowScanDepth in order to change the number of rows to be scanned.
SchemaRegistry	Setting TypeDetectionScheme to SchemaRegistry will determine will make use of the Schema Registry API and use a list of predefined AVRO schemas.
MessageOnly	Setting TypeDetectionScheme to MessageOnly will push all information as a single aggregate value on a column named Message.

Specifies how Avro data should be formatted during an INSERT.

Remarks

By default the Sync App writes out Avro data as a series of file blocks (as defined in the Avro specification). Confluent tools and libraries cannot decode this format and it cannot be used with Confluent schema validation. However, it is more compact because it allows multiple rows of Avro data to be stored in a single message.

Enable this option if you use Confluent schema validation, or otherwise require compatibility with Confluent tools and libraries. Each row inserted into an Avro topic will be a separate message and contain a reference to an schema stored in the registry.

Note that this cannot be enabled if there is no RegistryUrl set or RegistryUrl points to an AWS Glue schema registry. AWS Glue schemas do not support schema IDs which are a key part of how Confluent handles Avro data.

A filepath pointing to the JSON configuration file containing your custom views.

Remarks

User Defined Views are defined in a JSON-formatted configuration file called UserDefinedViews.json. The Sync App automatically detects the views specified in this file.

You can also have multiple view definitions and control them using the UserDefinedViews connection property. When you use this property, only the specified views are seen by the Sync App.

This User Defined View configuration file is formatted as follows:

• Each root element defines the name of a view.
• Each root element contains a child element, called query, which contains the custom SQL query for the view.

For example:

{
	"MyView": {
		"query": "SELECT * FROM SampleTable_1 WHERE MyColumn = 'value'"
	},
	"MyView2": {
		"query": "SELECT * FROM MyTable WHERE Id IN (1,2,3)"
	}
}

Use the UserDefinedViews connection property to specify the location of your JSON configuration file. For example:

"UserDefinedViews", C:\Users\yourusername\Desktop\tmp\UserDefinedViews.json

Note that the specified path is not embedded in quotation marks.

Specifies whether or not to validate schema registry topics against the Apache Kafka broker. Only has an effect when TypeDetectionScheme =SchemaRegistry.

Remarks

Schema registries can include metadata for topics that cannot be accessed in Kafka. This can happen because the topic doesn't exist on the broker. It is also possible that the principal the connection is authenticated to does not have access to the topic.

By default, the Sync App will get a list of schemas from the registry and then filter out any that the broker does not report. All the remaining valid topics are exposed as tables. You can disable this behavior by setting this option to false. This will report all schemas in the registry as tables regardless of whether they are accessible on the broker.