Adding a Connection to Apache Impala

To add a connection to Apache Impala:

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 Impala icon is not available, click the Add More icon to download and install the Apache Impala 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 Impala

In order to connect to Apache Impala, set the following:

• Server: The name or network address of the SQL Server instance.
• Port: The port for the connection to the Impala Server instance.
• ProtocolVersion: The Thrift protocol version to use when connecting to the Impala server.
• Database (optional): A default database to use when one is not supplied in the SQL query. This enables using table names without having to specify database.tablename in the query.
• Pagesize (optional): The number of results to pull per page from Apache Impala when selecting data.
• QueryPassthrough (optional): Indicates if the query should be passed to Impala as-is.
• UseSSL (optional): Set this to enable TLS/SSL.

  When QueryPassthrough is set to false (default), the CData ADO.NET Provider for Apache Impala will attempt to modify the query to conform to Impala required format.

Authenticating to Apache Impala

There are several ways to authenticate to Apache Impala including:

• NoSasl
• LDAP
• Kerberos

NoSasl

When using NoSasl, no authentication is performed. It is used when you are connecting to a server from a trusted location such as a test machine on your local network. By default, NoSasl is as the default AuthScheme, so no additional connection properties need to be set.

LDAP

To authenticate with LDAP, set the following connection properties:

• AuthScheme: Set this to LDAP.
• User: Set this to user to login as.
• Password: Set this to the password of the user.

To authenticate, set User, Password, and AuthScheme. If the LDAP server enables the Unauthenticated Authentication Mechanism of Simple Bind, the Password is optional instead of required.

Kerberos

Set the AuthScheme property to Kerberos. Please see Using Kerberos for details about how to authenticate with Kerberos.

Kerberos

To authenticate to Apache Impala with Kerberos, set AuthScheme to KERBEROS.

Authenticating to Apache Impala via Kerberos requires you to define authentication properties and to choose how Kerberos should retrieve authentication tickets.

Retrieve Kerberos Tickets

Kerberos tickets are used to authenticate the requester's identity. The use of tickets instead of formal logins/passwords eliminates the need to store passwords locally or send them over a network. Users are reauthenticated (tickets are refreshed) whenever they log in at their local computer or enter kinit USER at the command prompt.

The Sync App provides three ways to retrieve the required Kerberos ticket, depending on whether or not the KRB5CCNAME and/or KerberosKeytabFile variables exist in your environment.

MIT Kerberos Credential Cache File

This option enables you to use the MIT Kerberos Ticket Manager or kinit command to get tickets. With this option there is no need to set the User or Password connection properties.

This option requires that KRB5CCNAME has been created in your system.

To enable ticket retrieval via MIT Kerberos Credential Cache Files:

1. Ensure that the KRB5CCNAME variable is present in your environment.
2. Set KRB5CCNAME to a path that points to your credential cache file. (For example, C:\krb_cache\krb5cc_0 or /tmp/krb5cc_0.) The credential cache file is created when you use the MIT Kerberos Ticket Manager to generate your ticket.
3. To obtain a ticket:
   1. Open the MIT Kerberos Ticket Manager application.
   2. Click Get Ticket.
   3. Enter your principal name and password.
   4. Click OK.

   If the ticket is successfully obtained, the ticket information appears in Kerberos Ticket Manager and is stored in the credential cache file.

The Sync App uses the cache file to obtain the Kerberos ticket to connect to Apache Impala.

Note: If you would prefer not to edit KRB5CCNAME, you can use the KerberosTicketCache property to set the file path manually. After this is set, the Sync App uses the specified cache file to obtain the Kerberos ticket to connect to Apache Impala.

Keytab File

If your environment lacks the KRB5CCNAME environment variable, you can retrieve a Kerberos ticket using a Keytab File.

To use this method, set the User property to the desired username, and set the KerberosKeytabFile property to a file path pointing to the keytab file associated with the user.

User and Password

If your environment lacks the KRB5CCNAME environment variable and the KerberosKeytabFile property has not been set, you can retrieve a ticket using a user and password combination.

To use this method, set the User and Password properties to the user/password combination that you use to authenticate with Apache Impala.

Enabling Cross-Realm Authentication

More complex Kerberos environments can require cross-realm authentication where multiple realms and KDC servers are used. For example, they might use one realm/KDC for user authentication, and another realm/KDC for obtaining the service ticket.

To enable this kind of cross-realm authentication, set the KerberosRealm and KerberosKDC properties to the values required for user authentication. Also, set the KerberosServiceRealm and KerberosServiceKDC properties to the values required to obtain the service ticket.

Troubleshooting Performance

You may experience slow performance when querying large tables.

If you have a version of Apache Impala prior to version 3.4.0 installed, the following performance optimization is not possible. This is because these older versions are capped at a pagesize of 1024.

If you have Apache Impala version 3.4.0 or newer installed, follow this procedure to improve performance:

1. Set the Pagesize connection property to a comfortably high value. The default pagesize in versions 3.4.0 and later is 10000. A higher value will result in improved performance at the cost of addtional memory usage.
2. Enable result spooling by executing the following query:
   

   SET SPOOL_QUERY_RESULTS = TRUE

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

User Defined Views

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

SSL Configuration

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

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 Impala and then processes the rest of the query in memory (client-side).

For further information, see Query Processing.

Logging

For an overview of configuration settings that can be used to refine CData logging, see Logging. Only two connection properties are required for basic logging, but there are numerous features that support more refined logging, which enables you to use the LogModules connection property to specify subsets of information to be logged.

Customizing the SSL Configuration

To enable TLS, set UseSSL to True.

With this configuration, the Sync App attempts to negotiate TLS with the server. The server certificate is validated against the default system trusted certificate store. You can override how the certificate gets validated using the SSLServerCert connection property.

To specify another certificate, see the SSLServerCert connection property.

Connecting Through a Firewall or Proxy

HTTP Proxies

To authenticate to an HTTP proxy, set the following:

• ProxyServer: the hostname or IP address of the proxy server that you want to route HTTP traffic through.
• ProxyPort: the TCP port that the proxy server is running on.
• ProxyAuthScheme: the authentication method the Sync App uses when authenticating to the proxy server.
• ProxyUser: the username of a user account registered with the proxy server.
• ProxyPassword: the password associated with the ProxyUser.

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.

The Sync App models Apache Impala instances as relational databases. The Sync App leverages the Impala Server Thrift API, to enable bidirectional access to Apache Impala data through SQL. Impala Server 2.2.0 and above are supported.

Discovering Schemas

The CData Sync App dynamically obtains the Apache Impala schemas. Reconnect to load any changes in the metadata, such as added or removed columns or changes in data type.

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

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Property	Description
AuthScheme	The authentication scheme used. Accepted values are NoSasl, LDAP, Kerberos and JWTToken.
Server	The name of the server running SQL Server.
Port	The port for the connection to the Impala Server instance.
User	The username used to authenticate with Impala.
Password	The password used to authenticate with Impala.
ProtocolVersion	The Thrift protocol version to use when connecting to the Impala server.
Database	The name of the Impala database to use by default.
TransportMode	The transport mode to use to communicate with the Impala server. Accepted entries are BINARY and HTTP.
JWTToken	The JWT token to use for authentication.

Kerberos

---

Property	Description
KerberosKDC	The Kerberos Key Distribution Center (KDC) service used to authenticate the user.
KerberosRealm	The Kerberos Realm used to authenticate the user.
KerberosSPN	The service principal name (SPN) for the Kerberos Domain Controller.
KerberosUser	The principal name for the Kerberos Domain Controller. Used in the format host/user@realm.
KerberosKeytabFile	The Keytab file containing your pairs of Kerberos principals and encrypted keys.
KerberosServiceRealm	The Kerberos realm of the service.
KerberosServiceKDC	The Kerberos KDC of the service.
KerberosTicketCache	The full file path to an MIT Kerberos credential cache file.

SSL

---

Property	Description
SSLClientCert	Specifies the TLS/SSL client certificate store for SSL Client Authentication (2-way SSL). This property works in conjunction with other SSL-related properties to establish a secure connection.
SSLClientCertType	Specifies the type of key store containing the TLS/SSL client certificate for SSL Client Authentication. Choose from a variety of key store formats depending on your platform and certificate source.
SSLClientCertPassword	Specifes the password required to access the TLS/SSL client certificate store. Use this property if the selected certificate store type requires a password for access.
SSLClientCertSubject	Specifes the subject of the TLS/SSL client certificate to locate it in the certificate store. Use a comma-separated list of distinguished name fields, such as CN=www.server.com, C=US. The wildcard * selects the first certificate in the store.
SSLServerCert	Specifies the certificate to be accepted from the server when connecting using TLS/SSL.

Firewall

---

Property	Description
FirewallType	Specifies the protocol the provider uses to tunnel traffic through a proxy-based firewall.
FirewallServer	Identifies the IP address, DNS name, or host name of a proxy used to traverse a firewall and relay user queries to network resources.
FirewallPort	Specifies the TCP port to be used for a proxy-based firewall.
FirewallUser	Identifies the user ID of the account authenticating to a proxy-based firewall.
FirewallPassword	Specifies the password of the user account authenticating to a proxy-based firewall.

Proxy

---

Property	Description
ProxyAutoDetect	Specifies whether the provider checks your system proxy settings for existing proxy server configurations, rather than using a manually specified proxy server.
ProxyServer	The hostname or IP address of the proxy server that you want to route HTTP traffic through.
ProxyPort	The TCP port on your specified proxy server (set in the ProxyServer connection property) that has been reserved for routing HTTP traffic to and from the client.
ProxyAuthScheme	Specifies the authentication method the provider uses when authenticating to the proxy server specified in the ProxyServer connection property.
ProxyUser	The username of a user account registered with the proxy server specified in the ProxyServer connection property.
ProxyPassword	The password associated with the user specified in the ProxyUser connection property.
ProxySSLType	The SSL type to use when connecting to the proxy server specified in the ProxyServer connection property.
ProxyExceptions	A semicolon separated list of destination hostnames or IPs that are exempt from connecting through the proxy server set in the ProxyServer connection property.

Logging

---

Property	Description
LogModules	Specifies the core modules to include in the log file. Use a semicolon-separated list of module names. By default, all modules are logged.

Schema

---

Property	Description
Location	Specifies the location of a directory containing schema files that define tables, views, and stored procedures. Depending on your service's requirements, this may be expressed as either an absolute path or a relative path.
BrowsableSchemas	Optional setting that restricts the schemas reported to a subset of all available schemas. For example, BrowsableSchemas=SchemaA,SchemaB,SchemaC .
Tables	Optional setting that restricts the tables reported to a subset of all available tables. For example, Tables=TableA,TableB,TableC .
Views	Optional setting that restricts the views reported to a subset of the available tables. For example, Views=ViewA,ViewB,ViewC .

Miscellaneous

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Property	Description
HTTPPath	The path component of the URL endpoint when using HTTP TransportMode.
JGSSPrincipalAsDBUser	Whether to use the Kerberos principal as the database username. Only applies when UseJGSS is enabled.
MaxRows	Specifies the maximum rows returned for queries without aggregation or GROUP BY.
Other	Specifies additional hidden properties for specific use cases. These are not required for typical provider functionality. Use a semicolon-separated list to define multiple properties.
Pagesize	Specifies the maximum number of results to return from Apache Impala, per page. This setting overrides the default page size set by the datasource, which is optimized for most use cases.
PseudoColumns	Specifies the pseudocolumns to expose as table columns. Use the format 'TableName=ColumnName;TableName=ColumnName'. The default is an empty string, which disables this property.
QueryPassthrough	This option passes the query to the Apache Impala server as is.
ServerTimeZone	Defines the timezone used by the server for conversions between UTC and local time.
Timeout	Specifies the maximum time, in seconds, that the provider waits for a server response before throwing a timeout error. The default is 60 seconds. Set to 0 to disable the timeout.
UseJGSS	Specify whether to use native Java Kerberos Authentication (JGSS) for Kerberos Authentication.
UserDefinedViews	Specifies a filepath to a JSON configuration file defining custom views. The provider automatically detects and uses the views specified in this file.
UseSSL	Specifies whether to use SSL Encryption when connecting to Impala.

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

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Property	Description
AuthScheme	The authentication scheme used. Accepted values are NoSasl, LDAP, Kerberos and JWTToken.
Server	The name of the server running SQL Server.
Port	The port for the connection to the Impala Server instance.
User	The username used to authenticate with Impala.
Password	The password used to authenticate with Impala.
ProtocolVersion	The Thrift protocol version to use when connecting to the Impala server.
Database	The name of the Impala database to use by default.
TransportMode	The transport mode to use to communicate with the Impala server. Accepted entries are BINARY and HTTP.
JWTToken	The JWT token to use for authentication.

The authentication scheme used. Accepted values are NoSasl, LDAP, Kerberos and JWTToken.

Remarks

The AuthScheme used to authenticate with Impala.

NoSasl (default)	default
LDAP	Used when the enable_ldap_auth property is set to true and ldap_uri property is not empty.
Kerberos	Used when the keytab_file property is is not empty.
JWTToken	Used when the impala server enables the JWT authentication.

The name of the server running SQL Server.

Remarks

Set this property to the name or network address of the SQL Server instance.

The port for the connection to the Impala Server instance.

Remarks

When using BINARY TransportMode, this property should be set to the value in the 'hs2_port'(default 21050) property of the impala configuration (http://host:25000/varz).

When using HTTP TransportMode, this property should be set to the value in the 'hs2_http_port'(default 28000) property of the impala configuration (http://host:25000/varz).

The username used to authenticate with Impala.

Remarks

The username used to authenticate with Impala.

The password used to authenticate with Impala.

Remarks

The password used to authenticate with Impala.

The Thrift protocol version to use when connecting to the Impala server.

Remarks

The most efficient protocol version will be determined automatically by the CData Sync App upon connecting to Impala. This property allows you to explicitly specify the version to use and overrides the version determined by the CData Sync App.

The name of the Impala database to use by default.

Remarks

When specified, the CData Sync App will issue a 'USE [Database]' command upon connecting to Impala. This will be the database schema used when executing queries that do not have a schema explicitly specified.

To execute queries on other schemas, the schema can be explicitly specified in the statement.

When Database is not set, the 'default' database schema will be used (no 'USE' statement is issued to Impala in this case).

The transport mode to use to communicate with the Impala server. Accepted entries are BINARY and HTTP.

Remarks

The transport mode used to communicate with the Impala server.

The JWT token to use for authentication.

Remarks

In that case the Sync App will not generate the token itself, but use the token from the connection.

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

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Property	Description
KerberosKDC	The Kerberos Key Distribution Center (KDC) service used to authenticate the user.
KerberosRealm	The Kerberos Realm used to authenticate the user.
KerberosSPN	The service principal name (SPN) for the Kerberos Domain Controller.
KerberosUser	The principal name for the Kerberos Domain Controller. Used in the format host/user@realm.
KerberosKeytabFile	The Keytab file containing your pairs of Kerberos principals and encrypted keys.
KerberosServiceRealm	The Kerberos realm of the service.
KerberosServiceKDC	The Kerberos KDC of the service.
KerberosTicketCache	The full file path to an MIT Kerberos credential cache file.

The Kerberos Key Distribution Center (KDC) service used to authenticate the user.

Remarks

The Kerberos properties are used when using SPNEGO or Windows Authentication. The Sync App will request session tickets and temporary session keys from the Kerberos KDC service. The Kerberos KDC service is conventionally colocated with the domain controller.

If Kerberos KDC is not specified, the Sync App will attempt to detect these properties automatically from the following locations:

• KRB5 Config File (krb5.ini/krb5.conf): If the KRB5_CONFIG environment variable is set and the file exists, the Sync App will obtain the KDC from the specified file. Otherwise, it will attempt to read from the default MIT location based on the OS: C:\ProgramData\MIT\Kerberos5\krb5.ini (Windows) or /etc/krb5.conf (Linux).
• Domain Name and Host: If the Kerberos Realm and Kerberos KDC could not be inferred from another location, the Sync App will infer them from the configured domain name and host.

The Kerberos Realm used to authenticate the user.

Remarks

The Kerberos properties are used when using SPNEGO or Windows Authentication. The Kerberos Realm is used to authenticate the user with the Kerberos Key Distribution Service (KDC). The Kerberos Realm can be configured by an administrator to be any string, but conventionally it is based on the domain name.

If Kerberos Realm is not specified, the Sync App will attempt to detect these properties automatically from the following locations:

• KRB5 Config File (krb5.ini/krb5.conf): If the KRB5_CONFIG environment variable is set and the file exists, the Sync App will obtain the default realm from the specified file. Otherwise, it will attempt to read from the default MIT location based on the OS: C:\ProgramData\MIT\Kerberos5\krb5.ini (Windows) or /etc/krb5.conf (Linux)
• Domain Name and Host: If the Kerberos Realm and Kerberos KDC could not be inferred from another location, the Sync App will infer them from the user-configured domain name and host. This might work in some Windows environments.

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

Remarks

If the SPN on the Kerberos Domain Controller is not the same as the URL that you are authenticating to, use this property to set the SPN.

The principal name for the Kerberos Domain Controller. Used in the format host/user@realm.

Remarks

If the user you are using for the database doesn't match the user that is in the Kerberos database, this should be set to the Kerberos principal name.

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 Kerberos realm of the service.

Remarks

The KerberosServiceRealm is the specify the service Kerberos realm when using cross-realm Kerberos authentication.

In most cases, a single realm and KDC machine are used to perform the Kerberos authentication and this property is not required.

This property is available for complex setups where a different realm and KDC machine are used to obtain an authentication ticket (AS request) and a service ticket (TGS request).

The Kerberos KDC of the service.

Remarks

The KerberosServiceKDC is used to specify the service Kerberos KDC when using cross-realm Kerberos authentication.

In most cases, a single realm and KDC machine are used to perform the Kerberos authentication and this property is not required.

This property is available for complex setups where a different realm and KDC machine are used to obtain an authentication ticket (AS request) and a service ticket (TGS request).

The full file path to an MIT Kerberos credential cache file.

Remarks

This property can be set if you wish to use a credential cache file that was created using the MIT Kerberos Ticket Manager or kinit command.

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

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Property	Description
SSLClientCert	Specifies the TLS/SSL client certificate store for SSL Client Authentication (2-way SSL). This property works in conjunction with other SSL-related properties to establish a secure connection.
SSLClientCertType	Specifies the type of key store containing the TLS/SSL client certificate for SSL Client Authentication. Choose from a variety of key store formats depending on your platform and certificate source.
SSLClientCertPassword	Specifes the password required to access the TLS/SSL client certificate store. Use this property if the selected certificate store type requires a password for access.
SSLClientCertSubject	Specifes the subject of the TLS/SSL client certificate to locate it in the certificate store. Use a comma-separated list of distinguished name fields, such as CN=www.server.com, C=US. The wildcard * selects the first certificate in the store.
SSLServerCert	Specifies the certificate to be accepted from the server when connecting using TLS/SSL.

Specifies the TLS/SSL client certificate store for SSL Client Authentication (2-way SSL). This property works in conjunction with other SSL-related properties to establish a secure connection.

Remarks

This property specifies the client certificate store for SSL Client Authentication. Use this property alongside SSLClientCertType, which defines the type of the certificate store, and SSLClientCertPassword, which specifies the password for password-protected stores. When SSLClientCert is set and SSLClientCertSubject is configured, the driver searches for a certificate matching the specified subject.

Certificate store designations vary by platform. On Windows, certificate stores are identified by names such as MY (personal certificates), while in Java, the certificate store is typically a file containing certificates and optional private keys.

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.

For PFXFile types, set this property to the filename. For PFXBlob types, set this property to the binary contents of the file in PKCS12 format.

Specifies the type of key store containing the TLS/SSL client certificate for SSL Client Authentication. Choose from a variety of key store formats depending on your platform and certificate source.

Remarks

This property determines the format and location of the key store used to provide the client certificate. Supported values include platform-specific and universal key store formats. The available values and their usage are:

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.
BCFKSFILE	The certificate store is the name of a file that contains an Bouncy Castle keystore.
BCFKSBLOB	The certificate store is a string (base-64-encoded) that contains a Bouncy Castle keystore.

Specifes the password required to access the TLS/SSL client certificate store. Use this property if the selected certificate store type requires a password for access.

Remarks

This property provides the password needed to open a password-protected certificate store. This property is necessary when using certificate stores that require a password for decryption, as is often recommended for PFX or JKS type stores.

If the certificate store type does not require a password, for example USER or MACHINE on Windows, this property can be left blank. Ensure that the password matches the one associated with the specified certificate store to avoid authentication errors.

Specifes the subject of the TLS/SSL client certificate to locate it in the certificate store. Use a comma-separated list of distinguished name fields, such as CN=www.server.com, C=US. The wildcard * selects the first certificate in the store.

Remarks

This property determines which client certificate to load based on its subject. The Sync App searches for a certificate that exactly matches the specified subject. If no exact match is found, the Sync App looks for certificates containing the value of the subject. If no match is found, no certificate is selected.

The subject should follow the standard format of a comma-separated list of distinguished name fields and values. For example, CN=www.server.com, OU=Test, C=US. Common fields include the following:

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

Note: If any field contains special characters, such as commas, the value must be quoted. For example: CN="Example, Inc.", C=US.

Specifies the certificate to be accepted from the server 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	Specifies the protocol the provider uses to tunnel traffic through a proxy-based firewall.
FirewallServer	Identifies the IP address, DNS name, or host name of a proxy used to traverse a firewall and relay user queries to network resources.
FirewallPort	Specifies the TCP port to be used for a proxy-based firewall.
FirewallUser	Identifies the user ID of the account authenticating to a proxy-based firewall.
FirewallPassword	Specifies the password of the user account authenticating to a proxy-based firewall.

Specifies the protocol the provider uses to tunnel traffic through a proxy-based firewall.

Remarks

A proxy-based firewall (or proxy firewall) is a network security device that acts as an intermediary between user requests and the resources they access. The proxy accepts the request of an authenticated user, tunnels through the firewall, and transmits the request to the appropriate server.

Because the proxy evaluates and transfers data backets on behalf of the requesting users, the users never connect directly with the servers, only with the proxy.

Note: 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.

The following table provides port number information for each of the supported protocols.

Protocol	Default Port	Description
TUNNEL	80	The port where the Sync App opens a connection to Apache Impala. Traffic flows back and forth via the proxy at this location.
SOCKS4	1080	The port where the Sync App opens a connection to Apache Impala. SOCKS 4 then passes theFirewallUser value to the proxy, which determines whether the connection request should be granted.
SOCKS5	1080	The port where the Sync App sends data to Apache Impala. If the SOCKS 5 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.

Identifies the IP address, DNS name, or host name of a proxy used to traverse a firewall and relay user queries to network resources.

Remarks

A proxy-based firewall (or proxy firewall) is a network security device that acts as an intermediary between user requests and the resources they access. The proxy accepts the request of an authenticated user, tunnels through the firewall, and transmits the request to the appropriate server.

Because the proxy evaluates and transfers data backets on behalf of the requesting users, the users never connect directly with the servers, only with the proxy.

Specifies the TCP port to be used for a proxy-based firewall.

Remarks

A proxy-based firewall (or proxy firewall) is a network security device that acts as an intermediary between user requests and the resources they access. The proxy accepts the request of an authenticated user, tunnels through the firewall, and transmits the request to the appropriate server.

Because the proxy evaluates and transfers data backets on behalf of the requesting users, the users never connect directly with the servers, only with the proxy.

Identifies the user ID of the account authenticating to a proxy-based firewall.

Remarks

A proxy-based firewall (or proxy firewall) is a network security device that acts as an intermediary between user requests and the resources they access. The proxy accepts the request of an authenticated user, tunnels through the firewall, and transmits the request to the appropriate server.

Because the proxy evaluates and transfers data backets on behalf of the requesting users, the users never connect directly with the servers, only with the proxy.

Specifies the password of the user account authenticating to a proxy-based firewall.

Remarks

A proxy-based firewall (or proxy firewall) is a network security device that acts as an intermediary between user requests and the resources they access. The proxy accepts the request of an authenticated user, tunnels through the firewall, and transmits the request to the appropriate server.

Because the proxy evaluates and transfers data backets on behalf of the requesting users, the users never connect directly with the servers, only with the proxy.

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

---

Property	Description
ProxyAutoDetect	Specifies whether the provider checks your system proxy settings for existing proxy server configurations, rather than using a manually specified proxy server.
ProxyServer	The hostname or IP address of the proxy server that you want to route HTTP traffic through.
ProxyPort	The TCP port on your specified proxy server (set in the ProxyServer connection property) that has been reserved for routing HTTP traffic to and from the client.
ProxyAuthScheme	Specifies the authentication method the provider uses when authenticating to the proxy server specified in the ProxyServer connection property.
ProxyUser	The username of a user account registered with the proxy server specified in the ProxyServer connection property.
ProxyPassword	The password associated with the user specified in the ProxyUser connection property.
ProxySSLType	The SSL type to use when connecting to the proxy server specified in the ProxyServer connection property.
ProxyExceptions	A semicolon separated list of destination hostnames or IPs that are exempt from connecting through the proxy server set in the ProxyServer connection property.

Specifies whether the provider checks your system proxy settings for existing proxy server configurations, rather than using a manually specified proxy server.

Remarks

When this connection property is set to True, the Sync App checks your system proxy settings for existing proxy server configurations (no need to manually supply proxy server details).

This connection property takes precedence over other proxy settings. Set to False if you want to manually configure the Sync App to connect to a specific proxy server.

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

The hostname or IP address of the proxy server that you want to route HTTP traffic through.

Remarks

The Sync App only routes HTTP traffic through the proxy server specified in this connection property when ProxyAutoDetect is set to False. If ProxyAutoDetect is set to True, which is the default, the Sync App instead routes HTTP traffic through the proxy server specified in your system proxy settings.

The TCP port on your specified proxy server (set in the ProxyServer connection property) that has been reserved for routing HTTP traffic to and from the client.

Remarks

The Sync App only routes HTTP traffic through the proxy server port specified in this connection property when ProxyAutoDetect is set to False. If ProxyAutoDetect is set to True, which is the default, the Sync App instead routes HTTP traffic through the proxy server port specified in your system proxy settings.

For other proxy types, see FirewallType.

Specifies the authentication method the provider uses when authenticating to the proxy server specified in the ProxyServer connection property.

Remarks

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.
• NTLM: The Sync App retrieves an NTLM token.
• NEGOTIATE: The Sync App retrieves an NTLM or Kerberos token based on the applicable protocol for authentication.
• NONE: Set this when the ProxyServer does not require authentication.

For all values other than "NONE", you must also set the ProxyUser and ProxyPassword connection properties.

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

The username of a user account registered with the proxy server specified in the ProxyServer connection property.

Remarks

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

After selecting one of the available authentication types in ProxyAuthScheme, set this property as follows:

ProxyAuthScheme Value	Value to set for ProxyUser
BASIC	The user name of a user registered with the proxy server.
DIGEST	The user name of a user registered with the proxy server.
NEGOTIATE	The username of a Windows user who is a valid user in the domain or trusted domain that the proxy server is part of, in the format user@domain or domain\user.
NTLM	The username of a Windows user who is a valid user in the domain or trusted domain that the proxy server is part of, in the format user@domain or domain\user.
NONE	Do not set the ProxyPassword connection property.

The Sync App only uses this username if ProxyAutoDetect is set to False. If ProxyAutoDetect is set to True, which is the default, the Sync App instead uses the username specified in your system proxy settings.

The password associated with the user specified in the ProxyUser connection property.

Remarks

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

After selecting one of the available authentication types in ProxyAuthScheme, set this property as follows:

ProxyAuthScheme Value	Value to set for ProxyPassword
BASIC	The password associated with the proxy server user specified in ProxyUser.
DIGEST	The password associated with the proxy server user specified in ProxyUser.
NEGOTIATE	The password associated with the Windows user account specified in ProxyUser.
NTLM	The password associated with the Windows user account specified in ProxyUser.
NONE	Do not set the ProxyPassword connection property.

For SOCKS 5 authentication or tunneling, see FirewallType.

The Sync App only uses this password if ProxyAutoDetect is set to False. If ProxyAutoDetect is set to True, which is the default, the Sync App instead uses the password specified in your system proxy settings.

The SSL type to use when connecting to the proxy server specified in the ProxyServer connection property.

Remarks

This property determines when to use SSL for the connection to the HTTP proxy specified by ProxyServer. You can set this connection property to the following values :

AUTO	Default setting. If ProxyServer is set to an HTTPS URL, the Sync App uses the TUNNEL option. If ProxyServer is set to an HTTP URL, the component uses the NEVER option.
ALWAYS	The connection is always SSL enabled.
NEVER	The connection is not SSL enabled.
TUNNEL	The connection is made 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 proxy server set in the ProxyServer connection property.

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, set ProxyAutoDetect to False.

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

---

Property	Description
LogModules	Specifies the core modules to include in the log file. Use a semicolon-separated list of module names. By default, all modules are logged.

Specifies the core modules to include in the log file. Use a semicolon-separated list of module names. By default, all modules are logged.

Remarks

This property lets you customize the log file content by specifying the logging modules to include. Logging modules categorize logged information into distinct areas, such as query execution, metadata, or SSL communication. Each module is represented by a four-character code, with some requiring a trailing space for three-letter names.

For example, EXEC logs query execution, and INFO logs general provider messages. To include multiple modules, separate their names with semicolons as follows: INFO;EXEC;SSL.

The Verbosity connection property takes precedence over the module-based filtering specified by this property. Only log entries that meet the verbosity level and belong to the specified modules are logged. Leave this property blank to include all available modules in the log file.

For a complete list of available modules and detailed guidance on configuring logging, refer to the Advanced Logging section in Logging.

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

---

Property	Description
Location	Specifies the location of a directory containing schema files that define tables, views, and stored procedures. Depending on your service's requirements, this may be expressed as either an absolute path or a relative path.
BrowsableSchemas	Optional setting that restricts the schemas reported to a subset of all available schemas. For example, BrowsableSchemas=SchemaA,SchemaB,SchemaC .
Tables	Optional setting that restricts the tables reported to a subset of all available tables. For example, Tables=TableA,TableB,TableC .
Views	Optional setting that restricts the views reported to a subset of the available tables. For example, Views=ViewA,ViewB,ViewC .

Specifies the location of a directory containing schema files that define tables, views, and stored procedures. Depending on your service's requirements, this may be expressed as either an absolute path or a relative path.

Remarks

The Location property is only needed if you want to either customize definitions (for example, change a column name, ignore a column, etc.) or extend the data model with new tables, views, or stored procedures.

If left unspecified, the default location is %APPDATA%\\CData\\ApacheImpala Data Provider\\Schema, where %APPDATA% is set to the user's configuration directory:

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

Optional setting that restricts the schemas reported to a subset of all available schemas. For example, BrowsableSchemas=SchemaA,SchemaB,SchemaC .

Remarks

Listing all available database schemas can take extra time, thus degrading performance. Providing a list of schemas in the connection string saves time and improves performance.

Optional setting that restricts the tables reported to a subset of all available tables. For example, Tables=TableA,TableB,TableC .

Remarks

Listing all available tables from some databases can take extra time, thus degrading performance. Providing a list of tables in the connection string saves time and improves performance.

If there are lots of tables available and you already know which ones you want to work with, you can use this property to restrict your viewing to only those tables. To do this, 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: If you are connecting to a data source with multiple schemas or catalogs, you must specify each table you want to view by its fully qualified name. This avoids ambiguity between tables that may exist in multiple catalogs or schemas.

Optional setting that restricts the views reported to a subset of the available tables. For example, Views=ViewA,ViewB,ViewC .

Remarks

Listing all available views from some databases can take extra time, thus degrading performance. Providing a list of views in the connection string saves time and improves performance.

If there are lots of views available and you already know which ones you want to work with, you can use this property to restrict your viewing to only those views. To do this, 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: If you are connecting to a data source with multiple schemas or catalogs, you must specify each view you want to examine by its fully qualified name. This avoids ambiguity between views that may 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.

---

Property	Description
HTTPPath	The path component of the URL endpoint when using HTTP TransportMode.
JGSSPrincipalAsDBUser	Whether to use the Kerberos principal as the database username. Only applies when UseJGSS is enabled.
MaxRows	Specifies the maximum rows returned for queries without aggregation or GROUP BY.
Other	Specifies additional hidden properties for specific use cases. These are not required for typical provider functionality. Use a semicolon-separated list to define multiple properties.
Pagesize	Specifies the maximum number of results to return from Apache Impala, per page. This setting overrides the default page size set by the datasource, which is optimized for most use cases.
PseudoColumns	Specifies the pseudocolumns to expose as table columns. Use the format 'TableName=ColumnName;TableName=ColumnName'. The default is an empty string, which disables this property.
QueryPassthrough	This option passes the query to the Apache Impala server as is.
ServerTimeZone	Defines the timezone used by the server for conversions between UTC and local time.
Timeout	Specifies the maximum time, in seconds, that the provider waits for a server response before throwing a timeout error. The default is 60 seconds. Set to 0 to disable the timeout.
UseJGSS	Specify whether to use native Java Kerberos Authentication (JGSS) for Kerberos Authentication.
UserDefinedViews	Specifies a filepath to a JSON configuration file defining custom views. The provider automatically detects and uses the views specified in this file.
UseSSL	Specifies whether to use SSL Encryption when connecting to Impala.

The path component of the URL endpoint when using HTTP TransportMode.

Remarks

This property is used to specify the path component of the URL endpoint when using HTTP TransportMode.

Whether to use the Kerberos principal as the database username. Only applies when UseJGSS is enabled.

Remarks

The Sync App uses three pieces of information to authenticate the connection in Kerberos mode. When UseJGSS is enabled, only the service principal and database role may be configured within the Sync App. The user principal comes from the subject configured inside the Java security framework.

• The service principal that identifies the server itself (for example, hive/hiveserver.company.com)
• The user principal that identifies the user connecting to the server ([email protected])
• The database user that identifies a set of permissions within the database (bob)

By default the KerberosUser (or User) is the service principal. The database user is automatically derived from the user principal. For example, if you authenticate as the user principal [email protected] the database user is set to bob.

When JGSSPrincipalAsDBUser=false, the KerberosUser (or User) is the database role and the KerberosSPN is the service principal.

Specifies the maximum rows returned for queries without aggregation or GROUP BY.

Remarks

This property sets an upper limit on the number of rows the Sync App returns for queries that do not include aggregation or GROUP BY clauses. This limit ensures that queries do not return excessively large result sets by default.

When a query includes a LIMIT clause, the value specified in the query takes precedence over the MaxRows setting. If MaxRows is set to "-1", no row limit is enforced unless a LIMIT clause is explicitly included in the query.

This property is useful for optimizing performance and preventing excessive resource consumption when executing queries that could otherwise return very large datasets.

Specifies additional hidden properties for specific use cases. These are not required for typical provider functionality. Use a semicolon-separated list to define multiple properties.

Remarks

This property allows advanced users to configure hidden properties for specialized scenarios. These settings are not required for normal use cases but can address unique requirements or provide additional functionality. Multiple properties can be defined in a semicolon-separated list.

Note: It is strongly recommended to set these properties only when advised by the support team to address specific scenarios or issues.

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.

Specifies the maximum number of results to return from Apache Impala, per page. This setting overrides the default page size set by the datasource, which is optimized for most use cases.

Remarks

You may want to adjust the default pagesize to optimize results for a particular object or service endpoint you are querying. Be aware that increasing the page size may improve performance, but it could also result in higher memory consumption per page.

Specifies the pseudocolumns to expose as table columns. Use the format 'TableName=ColumnName;TableName=ColumnName'. The default is an empty string, which disables this property.

Remarks

This property allows you to define which pseudocolumns the Sync App exposes as table columns.

To specify individual pseudocolumns, use the following format: "Table1=Column1;Table1=Column2;Table2=Column3"

To include all pseudocolumns for all tables use: "*=*"

This option passes the query to the Apache Impala server as is.

Remarks

When this is set, queries are passed through directly to Apache Impala.

Defines the timezone used by the server for conversions between UTC and local time.

Remarks

This property is only supported in CData Sync App version 3.1 and up, and maps to the TIMEZONE query option. If not set, the server will use the default timezone, or it can be set to the name of an IANA Time Zone.

Specifies the maximum time, in seconds, that the provider waits for a server response before throwing a timeout error. The default is 60 seconds. Set to 0 to disable the timeout.

Remarks

This property controls the maximum time, in seconds, that the Sync App waits for an operation to complete before canceling it. If the timeout period expires before the operation finishes, the Sync App cancels the operation and throws an exception.

The timeout applies to each individual communication with the server rather than the entire query or operation. For example, a query could continue running beyond 60 seconds if each paging call completes within the timeout limit.

Setting this property to 0 disables the timeout, allowing operations to run indefinitely until they succeed or fail due to other conditions such as server-side timeouts, network interruptions, or resource limits on the server. Use this property cautiously to avoid long-running operations that could degrade performance or result in unresponsive behavior.

Specify whether to use native Java Kerberos Authentication (JGSS) for Kerberos Authentication.

Remarks

By default the Sync App uses an internal Kerberos implementation. Enabling this option makes it use Kerberos credentials attached to the current security Subject. The Sync App uses impersonation credentials if they are available (from Subject.getPrivateCredentials), otherwise the Subject's normal credentials are used.

Specifies a filepath to a JSON configuration file defining custom views. The provider automatically detects and uses the views specified in this file.

Remarks

This property allows you to define and manage custom views through a JSON-formatted configuration file called UserDefinedViews.json. These views are automatically recognized by the Sync App and enable you to execute custom SQL queries as if they were standard database views. The JSON file defines each view as a root element with a child element called "query", which contains the SQL query for the view. For example:

{
	"MyView": {
		"query": "SELECT * FROM [CData].[Default].Customers WHERE MyColumn = 'value'"
	},
	"MyView2": {
		"query": "SELECT * FROM MyTable WHERE Id IN (1,2,3)"
	}
}

You can define multiple views in a single file and specify the filepath using this property. For example: UserDefinedViews=C:\Path\To\UserDefinedViews.json. When you use this property, only the specified views are seen by the Sync App.

Refer to User Defined Views for more information.

Specifies whether to use SSL Encryption when connecting to Impala.

Remarks

Specifies whether to use SSL Encryption when connecting to Impala.

Apache Thrift Client v. 0.10.0

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Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.