The CData Sync App provides a straightforward way to continuously pipeline your Apache Impala data to any database, data lake, or data warehouse, making it easily available for Analytics, Reporting, AI, and Machine Learning.
The Apache Impala connector can be used from the CData Sync application to pull data from Apache Impala and move it to any of the supported destinations.
Create a connection to Apache Impala by navigating to the Connections page in the Sync App application and selecting the corresponding icon in the Add Connections panel. 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.
Required properties are listed under the Settings tab. The Advanced tab lists connection properties that are not typically required.
In order to connect to Apache Impala, set the following:
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.
There are several ways to authenticate to Apache Impala including:
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.
To authenticate with LDAP, set the following connection properties:
Set the AuthScheme property to Kerberos. Please see Using Kerberos for details about how to authenticate with Kerberos.
This section shows how to use the Sync App to authenticate using Kerberos.
To authenticate to Apache Impala using Kerberos, set the following properties:
You can use one of the following options to retrieve the required Kerberos ticket.
This option enables you to use the MIT Kerberos Ticket Manager or kinit command to get tickets. Note that you do not need to set the User or Password connection properties with this option.
As an alternative to setting the KRB5CCNAME environment variable, you can directly set the file path using the KerberosTicketCache property. When set, the Sync App uses the specified cache file to obtain the Kerberos ticket to connect to Apache Impala.
If the KRB5CCNAME environment variable has not been set, you can retrieve a Kerberos ticket using a Keytab File. To do so, 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.
If both the KRB5CCNAME environment variable and the KerberosKeytabFile property have not been set, you can retrieve a ticket using a user and password combination. To do this, set the User and Password properties to the user/password combination that you use to authenticate with Apache Impala.
More complex Kerberos environments may require cross-realm authentication where multiple realms and KDC servers are used (e.g., where one realm/KDC is used for user authentication and another realm/KDC is used for obtaining the service ticket).
In such an environment, 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.
This section details a selection of advanced features of the Apache Impala Sync App.
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.
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.
Configure the Sync App for compliance with Firewall and Proxy, including Windows proxies and HTTP proxies. You can also set up tunnel connections.
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).
See Query Processing for more information.
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.
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.
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.
Set the following properties:
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.
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.
| Property | Description |
| AuthScheme | The authentication scheme used. Accepted values are NoSasl, LDAP and Kerberos. |
| 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. |
| 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. |
| 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. |
| Property | Description |
| SSLClientCert | The TLS/SSL client certificate store for SSL Client Authentication (2-way SSL). |
| 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. |
| SSLServerCert | The certificate to be accepted from the server when connecting using TLS/SSL. |
| 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. |
| Property | Description |
| ProxyAutoDetect | This indicates whether to use the system proxy settings or not. This takes precedence over other proxy settings, so you'll need to set ProxyAutoDetect to FALSE in order use custom proxy settings. |
| 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 . |
| Property | Description |
| LogModules | Core modules to be included in the log file. |
| 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. |
| Property | Description |
| HTTPPath | The path component of the URL endpoint when using HTTP TransportMode. |
| MaxRows | Limits the number of rows returned rows when no aggregation or group by is used in the query. This helps avoid performance issues at design time. |
| Other | These hidden properties are used only in specific use cases. |
| Pagesize | The maximum number of results to return per page from Apache Impala. |
| PseudoColumns | This property indicates whether or not to include pseudo columns as columns to the table. |
| QueryPassthrough | This option passes the query to the Apache Impala server as is. |
| Timeout | The value in seconds until the timeout error is thrown, canceling the operation. |
| UserDefinedViews | A filepath pointing to the JSON configuration file containing your custom views. |
| 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.
| Property | Description |
| AuthScheme | The authentication scheme used. Accepted values are NoSasl, LDAP and Kerberos. |
| 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. |
The authentication scheme used. Accepted values are NoSasl, LDAP and Kerberos.
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. |
The name of the server running SQL Server.
Set this property to the name or network address of the SQL Server instance.
The port for the connection to the Impala Server instance.
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.
The username used to authenticate with Impala.
The password used to authenticate with Impala.
The password used to authenticate with Impala.
The Thrift protocol version to use when connecting to the Impala server.
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.
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.
The transport mode used to communicate with the Impala server.
This section provides a complete list of the Kerberos properties you can configure in the connection string for this provider.
| 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. |
| 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.
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:
The Kerberos Realm used to authenticate the user.
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:
The service principal name (SPN) for the Kerberos Domain Controller.
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 Keytab file containing your pairs of Kerberos principals and encrypted keys.
The Keytab file containing your pairs of Kerberos principals and encrypted keys.
The Kerberos realm of the service.
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.
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.
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.
| Property | Description |
| SSLClientCert | The TLS/SSL client certificate store for SSL Client Authentication (2-way SSL). |
| 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. |
| SSLServerCert | The certificate to be accepted from the server when connecting using TLS/SSL. |
The TLS/SSL client certificate store for SSL Client Authentication (2-way SSL).
The name of the certificate store for the client certificate.
The SSLClientCertType field specifies the type of the certificate store specified by SSLClientCert. If the store is password protected, specify the password in SSLClientCertPassword.
SSLClientCert is used in conjunction with the SSLClientCertSubject field in order to specify client certificates. If SSLClientCert has a value, and SSLClientCertSubject is set, a search for a certificate is initiated. See SSLClientCertSubject 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 containing the TLS/SSL client certificate.
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.
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.
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.
The certificate to be accepted from the server when connecting using TLS/SSL.
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.
| 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.
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 Impala 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.
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.
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.
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.
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.
| Property | Description |
| ProxyAutoDetect | This indicates whether to use the system proxy settings or not. This takes precedence over other proxy settings, so you'll need to set ProxyAutoDetect to FALSE in order use custom proxy settings. |
| 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. This takes precedence over other proxy settings, so you'll need to set ProxyAutoDetect to FALSE in order use custom proxy settings.
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.
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.
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.
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:
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.
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.
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.
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 .
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.
| Property | Description |
| LogModules | Core modules to be included in the log file. |
Core modules to be included in the log file.
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.
| 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.
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\\ApacheImpala Data Provider\\Schema" with %APPDATA% being set to the user's configuration directory:
This property restricts the schemas reported to a subset of the available schemas. For example, BrowsableSchemas=SchemaA,SchemaB,SchemaC.
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.
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.
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.
| Property | Description |
| HTTPPath | The path component of the URL endpoint when using HTTP TransportMode. |
| MaxRows | Limits the number of rows returned rows when no aggregation or group by is used in the query. This helps avoid performance issues at design time. |
| Other | These hidden properties are used only in specific use cases. |
| Pagesize | The maximum number of results to return per page from Apache Impala. |
| PseudoColumns | This property indicates whether or not to include pseudo columns as columns to the table. |
| QueryPassthrough | This option passes the query to the Apache Impala server as is. |
| Timeout | The value in seconds until the timeout error is thrown, canceling the operation. |
| UserDefinedViews | A filepath pointing to the JSON configuration file containing your custom views. |
| UseSSL | Specifies whether to use SSL Encryption when connecting to Impala. |
The path component of the URL endpoint when using HTTP TransportMode.
This property is used to specify the path component of the URL endpoint when using HTTP TransportMode.
Limits the number of rows returned rows when no aggregation or group by is used in the query. This helps avoid performance issues at design time.
Limits the number of rows returned rows when no aggregation or group by is used in the query. This helps avoid performance issues at design time.
These hidden properties are used only in specific use cases.
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.
| 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 results to return per page from Apache Impala.
The Pagesize property affects the maximum number of results to return per page from Apache Impala. Setting a higher value may result in better performance at the cost of additional memory allocated per page consumed.
This property indicates whether or not to include pseudo columns as columns to the table.
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, "*=*".
This option passes the query to the Apache Impala server as is.
When this is set, queries are passed through directly to Apache Impala.
The value in seconds until the timeout error is thrown, canceling the operation.
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.
A filepath pointing to the JSON configuration file containing your custom views.
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:
For example:
{
"MyView": {
"query": "SELECT * FROM [CData].[Default].Customers 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"
Specifies whether to use SSL Encryption when connecting to Impala.
Specifies whether to use SSL Encryption when connecting to Impala.
Apache Thrift Client
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