Replication Distribution Agent

Article
10/31/2024

Applies to: SQL Server Azure SQL Database

The Replication Distribution Agent is an executable that moves the snapshot (for snapshot replication and transactional replication) and the transactions held in the distribution database tables (for transactional replication) to the destination tables at the Subscribers.

Note

Parameters can be specified in any order. When optional parameters aren't specified, values from predefined registry settings on the local computer are used.

Syntax

distrib [ -? ]
-Publisher server_name [ \instance_name ]
-PublisherDB publisher_database
-Subscriber server_name [ \instance_name ]
-SubscriberDB subscriber_database
[ -AltSnapshotFolder alt_snapshot_folder_path ]
[ -BcpBatchSize bcp_batch_size ]
[ -CommitBatchSize commit_batch_size ]
[ -CommitBatchThreshold commit_batch_threshold ]
[ -Continuous ]
[ -DefinitionFile def_path_and_file_name ]
[ -Distributor distributor ]
[ -DistributorLogin distributor_login ]
[ -DistributorPassword distributor_password ]
[ -DistributorSecurityMode [ 0 | 1 ] ]
[ -EncryptionLevel [ 0 | 1 | 2 ] ]
[ -ErrorFile error_path_and_file_name ]
[ -ExtendedEventConfigFile configuration_path_and_file_name ]
[ -FileTransferType [ 0 | 1 ] ]
[ -FtpAddress ftp_address ]
[ -FtpPassword ftp_password ]
[ -FtpPort ftp_port ]
[ -FtpUserName ftp_user_name ]
[ -HistoryVerboseLevel [ 0 | 1 | 2 | 3 ] ]
[ -Hostname host_name ]
[ -KeepAliveMessageInterval keep_alive_message_interval_seconds ]
[ -LoginTimeOut login_time_out_seconds ]
[ -MaxBcpThreads ]
[ -MaxDeliveredTransactions number_of_transactions ]
[ -MessageInterval message_interval ]
[ -MultiSubnetFailover [ 0 | 1 ] ]
[ -OledbStreamThreshold oledb_stream_threshold ]
[ -Output output_path_and_file_name ]
[ -OutputVerboseLevel [ 0 | 1 | 2 ] ]
[ -PacketSize packet_size ]
[ -PollingInterval polling_interval ]
[ -ProfileName profile_name ]
[ -Publication publication ]
[ -QueryTimeOut query_time_out_seconds ]
[ -QuotedIdentifier quoted_identifier ]
[ -SkipErrors native_error_id [ :...n ] ]
[ -SubscriberDatabasePath subscriber_path ]
[ -SubscriberLogin subscriber_login ]
[ -SubscriberPassword subscriber_password ]
[ -SubscriberSecurityMode [ 0 | 1 ] ]
[ -SubscriberType [ 0 | 1 | 3 ] ]
[ -SubscriptionStreams [ 1 | 2 | ...64 ] ]
[ -SubscriptionTableName subscription_table ]
[ -SubscriptionType [ 0 | 1 | 2 ] ]
[ -TransactionsPerHistory [ 0 | 1 | ...10000 ] ]
[ -UseDTS ]
[ -UseInprocLoader ]
[ -UseOledbStreaming ]

Arguments

-?

Prints all available parameters.

-Publisher server_name [ \instance_name ]

The name of the Publisher. Specify <server_name> for the default instance of Microsoft SQL Server on that server. Specify <server_name>\<instance_name> for a named instance of SQL Server on that server. If your publisher database is in an availability group (AG), this still reflects the original primary publisher server name due to sp_redirect_publisher. It doesn't reflect the AG listener name.

-PublisherDB publisher_database

The name of the Publisher database.

-Subscriber server_name [ \instance_name ]

The name of the Subscriber. Specify <server_name> for the default instance of SQL Server on that server. Specify <server_name>\<instance_name> for a named instance of SQL Server on that server. If your subscriber database is in an AG, this should reflect the AG listener name.

-SubscriberDB subscriber_database

The name of the Subscriber database.

-AltSnapshotFolder alt_snapshot_folder_path

The path to the folder that contains the initial snapshot for a subscription.

-BcpBatchSize bcp_batch_size

The number of rows to send in a bulk copy operation. When you perform a bcp in operation, the batch size is the number of rows to send to the server as one transaction, and also the number of rows that must be sent before the Distribution Agent logs a bcp progress message. When you perform a bcp out operation, a fixed batch size of 1000 is used.

-CommitBatchSize commit_batch_size

The number of transactions to be issued to the Subscriber before a COMMIT statement is issued. The default is 100 and the max is 10000. This parameter is ignored when the snapshot is applied on the subscriber by the Distribution Agent.

-CommitBatchThreshold commit_batch_threshold

The number of replication commands to be issued to the Subscriber before a COMMIT statement is issued. The default is 1000 and the max is 10000. This parameter is ignored when the snapshot is applied on the subscriber by the Distribution Agent.

-Continuous

Specifies whether the agent attempts to poll replicated transactions continually. If specified, the agent polls replicated transactions from the source at polling intervals, even if there are no transactions pending.

-DefinitionFile def_path_and_file_name

The path of the agent definition file. An agent definition file contains command prompt arguments for the agent. The content of the file is parsed as an executable file. Use double quotation marks (") to specify argument values containing arbitrary characters.

-Distributor distributor

The Distributor name. For Distributor (push) distribution, the name defaults to the name of the local Distributor. If your distributor database is in an AG, this should reflect the AG listener name.

-DistributorLogin distributor_login

The Distributor login name.

-DistributorPassword distributor_password

The Distributor password.

-DistributorSecurityMode [ 0 | 1 ]

Specifies the security mode of the Distributor. A value of 0 indicates SQL Server Authentication Mode, and a value of 1 indicates Windows Authentication Mode (default).

-EncryptionLevel [ 0 | 1 | 2 ]

The level of Transport Layer Security (TLS), previously known as Secure Sockets Layer (SSL), encryption used by the Distribution Agent when making connections.

EncryptionLevel value	Description
`0`	Specifies that TLS isn't used.
`1`	Specifies that TLS is used, but the agent doesn't verify that the TLS server certificate is signed by a trusted issuer.
`2`	Specifies that TLS is used, and that the certificate is verified.

A valid TLS certificate is defined with a fully qualified domain name of the SQL Server. In order for the agent to connect successfully when setting -EncryptionLevel to 2, create an alias on the local SQL Server. The 'Alias Name' parameter should be the server name and the 'Server' parameter should be set to the fully qualified name of the SQL Server.

For more information, see View and Modify Replication Security Settings.

-ErrorFile error_path_and_file_name

The path and file name of the error file generated by the Distribution Agent. This file is generated at any point where failure occurred while applying replication transactions at the Subscriber; errors that occur at the Publisher or Distributor aren't logged in this file. This file contains the failed replication transactions and associated error messages. When not specified, the error file is generated in the current directory of the Distribution Agent. The error file name is the name of the Distribution Agent with an .err extension. If the specified file name exists, error messages are appended to the file. This parameter can be a maximum of 256 Unicode characters.

-ExtendedEventConfigFile configuration_path_and_file_name

Specifies the path and file name for the extended events XML configuration file. The extended events configuration file allows you to configure sessions and enable events for tracking.

-FileTransferType [ 0 | 1 ]

Specifies the file transfer type. A value of 0 indicates UNC (universal naming convention), and a value of 1 indicates FTP (file transfer protocol).

-FtpAddress ftp_address

The network address of the FTP service for the Distributor. When not specified, DistributorAddress is used. If DistributorAddress isn't specified, Distributor is used.

-FtpPassword ftp_password

The user password used to connect to the FTP service.

-FtpPort ftp_port

The port number of the FTP service for the Distributor. When not specified, the default port number for FTP service (21) is used.

-FtpUserName ftp_user_name

The user name used to connect to the FTP service. When not specified, anonymous is used.

-HistoryVerboseLevel [ 0 | 1 | 2 | 3 ]

Specifies the amount of history logged during a distribution operation. You can minimize the performance effect of history logging by selecting 1.

HistoryVerboseLevel value	Description
`0`	Progress messages are written either to the console or to an output file. History records aren't logged in the distribution database.
`1` (default)	Always update a previous history message of the same status (startup, progress, success, and so on). If no previous record with the same status exists, insert a new record.
`2`	Insert new history records unless the record is for such things as idle messages or long-running job messages, in which case update the previous records.
`3`	Always insert new records, unless it's for idle messages.

-Hostname host_name

The host name used when connecting to the Publisher. This parameter can be a maximum of 128 Unicode characters.

-KeepAliveMessageInterval keep_alive_message_interval_seconds

The number of seconds before the history thread checks if any of the existing connections is waiting for a response from the server. This value can be decreased to avoid having the checkup agent mark the Distribution Agent as suspect when executing a long-running batch. The default is 300 seconds.

-LoginTimeOut login_time_out_seconds

The number of seconds before the login times out. The default is 15 seconds.

-MaxBcpThreads number_of_threads

Specifies the number of bulk copy operations that can be performed in parallel. The maximum number of threads and ODBC connections that exist simultaneously is the lesser of MaxBcpThreads or the number of bulk copy requests that appear in the synchronization transaction in the distribution database. MaxBcpThreads must have a value greater than 0 and has no hard-coded upper limit. The default is 2 times the number of processors, up to a maximum value of 8. When applying a snapshot that was generated at the Publisher using the concurrent snapshot option, one thread is used, regardless of the number you specify for MaxBcpThreads.

-MaxDeliveredTransactions number_of_transactions

The maximum number of push or pull transactions applied to Subscribers in one synchronization. A value of 0 indicates that the maximum is an infinite number of transactions. Other values can be used by Subscribers to shorten the duration of a synchronization being pulled from a Publisher.

If -MaxDeliveredTransactions and -Continuous are both specified, the Distribution Agent delivers the specified number of transactions and then stops (even though -Continuous is specified). You must restart the Distribution Agent after the job completes.

-MessageInterval message_interval

The time interval used for history logging. A history event is logged when one of these parameters is reached:

The TransactionsPerHistory value is reached after the last history event is logged.
The MessageInterval value is reached after the last history event is logged.

If there's no replicated transaction available at the source, the agent reports a no-transaction message to the Distributor. This option specifies how long the agent waits before reporting another no-transaction message. Agents always report a no-transaction message when they detect that there are no transactions available at the source after previously processing replicated transactions. The default is 60 seconds.

-MultiSubnetFailover

Applies to: SQL Server 2019 (15.x) and later versions.

Specifies whether the MultiSubnetFailover property is enabled or not. If your application is connecting to an AG on different subnets, setting MultiSubnetFailover=true provides faster detection of and connection to the (currently) active server.

-OledbStreamThreshold oledb_stream_threshold

Specifies the minimum size, in bytes, for binary large object data above which the data is bound as a stream. You must specify -UseOledbStreaming to use this parameter. Values can range from 400 bytes to 1,048,576 bytes, with a default of 16,384 bytes.

-Output output_path_and_file_name

The path of the agent output file. If the file name isn't provided, the output is sent to the console. If the specified file name exists, the output is appended to the file.

-OutputVerboseLevel [ 0 | 1 | 2 ]

Specifies whether the output should be verbose. If the verbose level is 0, only error messages are printed. If the verbose level is 1, all the progress report messages are printed. If the verbose level is 2 (default), all error messages and progress report messages are printed, which is useful for debugging.

-PacketSize packet_size

The packet size, in bytes. The default is 4096 (bytes).

-PollingInterval polling_interval

How often, in seconds, the distribution database is queried for replicated transactions. The default is 5 seconds.

-ProfileName profile_name

Specifies an agent profile to use for agent parameters. If ProfileName is NULL, the agent profile is disabled. If ProfileName isn't specified, the default profile for the agent type is used. For information, see Replication Agent Profiles.

-Publication publication

The name of the publication. This parameter is only valid if the publication is set to always have a snapshot available for new or reinitialized subscriptions.

-QueryTimeOut query_time_out_seconds

The number of seconds before the query times out. The default is 1,800 seconds.

-QuotedIdentifier quoted_identifier

Specifies the quoted identifier character to use. The first character of the value indicates the value the Distribution Agent uses. If QuotedIdentifier is used with no value, the Distribution Agent uses a space. If QuotedIdentifier isn't used, the Distribution Agent uses whatever quoted identifier the Subscriber supports.

-SkipErrors native_error_id [ :...n ]

A colon-separated list that specifies the error numbers to be skipped by this agent. This parameter is ignored when the snapshot is being applied on the subscriber by the Distribution Agent.

-SubscriberDatabasePath subscriber_database_path

The path to the Jet database (.mdb file) if SubscriberType is 2 (allows a connection to a Jet database without an ODBC Data Source Name (DSN)).

-SubscriberLogin subscriber_login

The Subscriber login name. If SubscriberSecurityMode is 0 (for SQL Server Authentication), this parameter must be specified.

-SubscriberPassword subscriber_password

The Subscriber password. If SubscriberSecurityMode is 0 (for SQL Server Authentication), this parameter must be specified.

-SubscriberSecurityMode [ 0 | 1 ]

Specifies the security mode of the Subscriber. A value of 0 indicates SQL Server Authentication, and a value of 1 indicates Windows Authentication Mode (default).

-SubscriberType [ 0 | 1 | 3 ]

Specifies the type of Subscriber connection used by the Distribution Agent.

SubscriberType value	Description
`0`	SQL Server
`1`	ODBC data source
`3`	OLE DB data source

-SubscriptionStreams [ 0 | 1 | 2 | ...64 ]

The number of connections allowed per Distribution Agent to apply batches of changes in parallel to a Subscriber, while maintaining many of the transactional characteristics present when using a single thread. For a SQL Server Publisher, a range of values from 1 to 64 is supported.

This parameter isn't supported or must be 0 for non-SQL Server Subscribers or peer-to-peer subscriptions. This parameter is ignored when the snapshot is being applied on the subscriber by the Distribution Agent.

If one of the connections fails to execute or commit, all connections abort the current batch, and the agent uses a single stream to retry the failed batches. Before this retry phase completes, there can be temporary transactional inconsistencies at the Subscriber. After the failed batches are successfully committed, the Subscriber is brought back to a state of transactional consistency.

Important

When you specify a value of 2 or greater for -SubscriptionStreams, the order in which transactions are received at the Subscriber might differ from the order in which they were made at the Publisher. If this behavior causes constraint violations during synchronization, you should use the NOT FOR REPLICATION option to disable the enforcement of constraints during synchronization. For more information, see Control Behavior of Triggers and Constraints in Synchronization.

Subscription streams don't work for articles configured to deliver Transact-SQL. To use subscription streams, configure articles to deliver stored procedure calls instead.

-SubscriptionTableName subscription_table

The name of the subscription table generated or used at the given Subscriber. When not specified, the MSreplication_subscriptions table is used. Use this option for database management systems (DBMS) that don't support long file names.

-SubscriptionType [ 0 | 1 | 2 ]

Specifies the subscription type for distribution. A value of 0 indicates a push subscription, a value of 1 indicates a pull subscription, and a value of 2 indicates an anonymous subscription.

-TransactionsPerHistory [ 0 | 1 | ... 10000 ]

Specifies the transaction interval for history logging. If the number of committed transactions after the last instance of history logging is greater than this option, a history message is logged. The default is 100. A value of 0 indicates infinite TransactionsPerHistory. See the preceding –MessageIntervalparameter.

-UseDTS

Must be specified as a parameter for a publication that allows data transformation.

-UseInprocLoader

Improves the performance of the initial snapshot by causing the Distribution Agent to use the BULK INSERT command when applying snapshot files to the Subscriber. This parameter is deprecated because it isn't compatible with the XML data type. If you aren't replicating XML data, this parameter can be used. This parameter can't be used with character mode snapshots or non- SQL Server Subscribers. If you use this parameter, the SQL Server service account at the Subscriber requires read permissions on the directory where the snapshot .bcp data files are located. When this parameter isn't used, the agent (for non- SQL Server Subscribers) or the ODBC driver loaded by the agent (for SQL Server Subscribers) reads from the files, so the security context of the SQL Server service account isn't used.

-UseOledbStream

When specified, enables the binding of binary large object data as a stream. Use -OledbStreamThreshold to specify the size, in bytes, above which a stream is used. UseOledbStreaming is enabled by default.

In SQL Server 2017 (14.x) CU 22 and later versions, UseOledbStreaming writes to the C:\Users\<DistributionAgentAccount>\AppData\Temp folder.

Before SQL Server 2017 (14.x) CU 22, UseOledbStreaming writes to the C:\Program Files\Microsoft SQL Server\<version>\COM folder.

In SQL Server 2019 (15.x) CU 29, SQL Server 2022 (16.x) CU 16, and later versions, you can disable OLE DB streaming by updating -UseOledbStreaming to 0 to avoid the error mentioned in Error message when you run the Distribution Agent in SQL Server.

Remarks

If you installed SQL Server Agent to run under a local system account rather than under a domain user account (the default), the service can only access the local computer. If the Distribution Agent that runs under SQL Server Agent is configured to use Windows Authentication Mode when it logs in to an instance of SQL Server, the Distribution Agent fails. The default setting is SQL Server Authentication. For information on changing security accounts, see View and Modify Replication Security Settings.

To start the Distribution Agent, execute distrib.exe from the command prompt. For information, see Replication Agent Executables Concepts.

Replication Agent Administration

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