Duration indicates whether the parameter value lasts for only the current transaction (T) or whether it lasts until changed (C).
R/W indicates whether the value can be only be read (R/O) or can be read and written/updated (R/W).
SYNC_APP_SCHEMA_VERSION
Each synchronizable catalog can have a schema version name as one of its properties. If master and replica catalogs have different schema version names, sending the synchronization messages between master and replica nodes fails.
The name of the property is SYNC_APP_SCHEMA_VERSION. This version name can be set using SET SYNC PARAMETER statement.
Examples:
SET SYNC PARAMETER SYNC_APP_SCHEMA_VERSION 'sputnik'; SET SYNC PARAMETER SYNC_APP_SCHEMA_VERSION NONE;
Factory value: None
Duration: C
R/W: R/W
SYNC_MODE
Each catalog has a read-only parameter named SYNC_MODE. Applications use this parameter to check the catalog mode. The parameter values are:
▪ MAINTENANCE, if the catalog is in maintenance sync mode
▪ NORMAL, if the catalog is not in maintenance sync mode
▪ NULL, if the catalog is not a master or a replica
You can change the catalog mode with statement:
SET SYNC MODE{NORMAL | MAINTENANCE}
Factory value: NORMAL
Duration: C
R/W: RO
SYS_TRAN_MAXRETRY
This parameter provides a way to handle concurrency conflicts and deadlocks, which occur when transactions update or delete rows. When this parameter is set, the server retries a transaction that has failed execution at the master due to a concurrency conflict. The value specifies the maximum number of retries.
You can set this value on the master by using the SET SYNC PARAMETER statement. If you set it on the master, it will be the default value used for all transactions propagated to that master. Note that this parameter only applies when the master executes propagated transactions received from the replica.
You can set this value on the replica by using the statement.
SAVE PROPERTY ...
to put the value on the bulletin board for the individual transaction. The value is propagated to the master bulletin board for that same transaction. Setting the parameter this way means that the value applies only to this particular transaction.
If the value is set both by the SAVE PROPERTY statement on the replica and the SET SYNC PARAMETER statement on the master, the SAVE PROPERTY statement on the replica takes precedence. The value that you set for a specific transaction takes precedence over the general default value on the master.
When SYS_TRAN_MAXRETRY reaches the limit, the offending transaction is marked as failed. A separate MESSAGE EXECUTE statement must be executed to start the transaction again.
SYS_TRAN_RETRYTIMEOUT is closely related to the SYS_TRAN_MAXRETRY parameter. See the discussion of SYS_TRAN_RETRYTIMEOUT below for details.
Factory value: The factory value is zero (0), which means that if the transaction fails, it is not retried. Valid values for the parameter are integers between 0 and 2147483647 (inclusive).
Duration: C
R/W: R/W
SYS_TRAN_RETRYTIMEOUT
This parameter is used in conjunction with the SYS_TRAN_MAXRETRY parameter. The SYS_TRAN_MAXRETRY parameter specifies the number of additional transaction attempts that occur after the transaction has failed at the master due to a concurrency conflict. The SYS_TRAN_RETRYTIMEOUT parameter sets the timeout (in seconds) that the master server waits before it tries the failed transaction (that was received from the replica) again. The value of this parameter can be set only in the master database using the SET SYNC PARAMETER statement. For details on SET SYNC PARAMETER, see SET SYNC PARAMETER
Factory value: The factory value is zero (0), which means that the master server does not wait between retries. Valid values for the parameter are any integer between 0 and 2147483647 (inclusive).