DBA_OB_TENANT_EVENT_HISTORY

Purpose

The DBA_OB_TENANT_EVENT_HISTORY view displays the historical operation records of the current tenant.

Columns

Sample tenant events

The following examples show tenant events in the TENANT ROLE CHANGE (primary/standby tenant switch), SERVICE NAME (service name), and DBMS_BALANCE modules.

The NAME and VALUE values of events vary depending on the module operations performed by users.

TENANT ROLE CHANGE

TENANT ROLE CHANGE module contains the following three operations: FAILOVER TO PRIMARY, SWITCHOVER TO PRIMARY, and SWITCHOVER TO STANDBY.

• FAILOVER TO PRIMARY operation

  When you initiate a FAILOVER TO PRIMARY operation, the following important events are recorded in the tenant event record table.

  • FAILOVER TO PRIMARY START

    This event records the specific time when the ALTER SYSTEM ACTIVATE STANDBY command is executed, along with the tenant information.

    Attribute	Attribute Value
    NAME1: STMT_STR	VALUE1: The command text entered by the user.
    NAME2: TENANT_INFO	VALUE2: The status or information of the tenant at the time the command is initiated.

  • FAILOVER TO PRIMARY END

    This event records the exact time when the ALTER SYSTEM ACTIVATE STANDBY command is completed, including the tenant information, the final state of the log stream, and the time taken for key steps.

    Attribute	Attribute Value
    NAME1: STMT_STR	VALUE1: The command text entered by the user.
    NAME2: TENANT_INFO	VALUE2: The status or information of the tenant at the end of the command.
    NAME3: FAILOVER_SCN	VALUE3: The synchronization point after the tenant fails over.
    NAME4: COST_DETAIL	VALUE4: The time taken for each stage of the command execution, in microseconds.
    NAME5: ALL_LS	VALUE5: The status of all log streams when the tenant modifies the ACCESS MODE.

• SWITCHOVER TO PRIMARY operation

  When you initiate a SWITCHOVER TO PRIMARY operation, the following important events are recorded in the tenant event record table.

  • SWITCHOVER TO PRIMARY START

    This event records the specific time when the ALTER SYSTEM SWITCHOVER TO PRIMARY command is executed, along with the tenant information.

    Attribute	Attribute Value
    NAME1: STMT_STR	VALUE1: The command text entered by the user.
    NAME2: TENANT_INFO	VALUE2: The status or information of the tenant at the time the command is initiated.

  • WAIT LOG SYNC

    This event records the information about log synchronization for the tenant. When you execute the ALTER SYSTEM SWITCHOVER TO PRIMARY command, the involved tenant must wait until all the latest log records are synchronized from the current primary tenant to ensure data consistency and integrity.

    Attribute	Attribute Value
    NAME1: IS_SYS_LS_SYNCED	VALUE1: Indicates whether the system log stream is synchronized.
    NAME2: IS_ALL_LS_SYNCED	VALUE2: Indicates whether all log streams are synchronized.
    NAME3: NON_SYNC_INFO	VALUE3: If there are unsynchronized log streams, the system displays the number of unsynchronized log streams and provides information about the five log streams with the slowest synchronization speed.

  • SWITCHOVER TO PRIMARY END

    This event records the exact time when the ALTER SYSTEM SWITCHOVER TO PRIMARY command is completed, including the tenant information, the final state of the log stream, and the time taken for key steps.

    Attribute	Attribute Value
    NAME1: STMT_STR	VALUE1: The command text entered by the user.
    NAME2: TENANT_INFO	VALUE2: The status or information of the tenant at the end of the command.
    NAME3: SWITCHOVER_SCN	VALUE3: The synchronization point after the tenant is switched over.
    NAME4: COST_DETAIL	VALUE4: The time taken for each stage of the command execution, in microseconds.
    NAME5: ALL_LS	VALUE5: The status of all log streams when the tenant modifies the ACCESS MODE.

• SWITCHOVER TO STANDBY operation

  When you initiate a SWITCHOVER TO STANDBY operation, the following important events are recorded in the tenant event record table.

  • SWITCHOVER TO STANDBY START

    This event records the specific time when the ALTER SYSTEM SWITCHOVER TO STANDBY command is executed, along with the tenant information.

    Attribute	Attribute Value
    NAME1: STMT_STR	VALUE1: The command text entered by the user.
    NAME2: TENANT_INFO	VALUE2: The status or information of the tenant at the time the command is initiated.

  • SWITCHOVER TO STANDBY END

    This event records the exact time when the ALTER SYSTEM SWITCHOVER TO STANDBY command is completed, including the tenant information, the final state of the log stream, and the time taken for key steps.

    Attribute	Attribute Value
    NAME1: STMT_STR	VALUE1: The command text entered by the user.
    NAME2: TENANT_INFO	VALUE2: The status or information of the tenant at the end of the command.
    NAME3: SWITCHOVER_SCN	VALUE3: The synchronization point after the tenant is switched over.
    NAME4: COST_DETAIL	VALUE4: The time taken for each stage of the command execution, in microseconds.
    NAME5: ALL_LS	VALUE5: The status of all log streams when the tenant modifies the ACCESS MODE.

SERVICE NAME

The SERVICE NAME module supports the CREATE SERVICE, DELETE SERVICE, START SERVICE, and STOP SERVICE operations.

You can use the TRACE_ID to trace the events of these operations. For example, you can find the event of creating a service and then trace the event by using the TRACE_ID to find out whether the service creation triggers a broadcast.

• CREATE SERVICE

  When a user tenant is created, the system records the following events.

  • BROADCAST SERVICE NAME

    This event records the content of the broadcast, the list of OBServer nodes that receive the broadcast, and the list of OBServer nodes that successfully receive the broadcast. When you execute the ALTER SYSTEM CREATE SERVICE command, the OBServer node that initiates the command broadcasts the current service name of the tenant to all OBServer nodes where the units of the tenant are located.

    Column	Description
    NAME1: EPOCH	VALUE1: the version of the current service name information of the tenant for the current broadcast
    NAME2: TARGET_SERVICE_NAME_ID	VALUE2: the service_name_id of the event that triggers the current broadcast
    NAME3: SERVICE_NAME_LIST	VALUE3: the current service name information of the tenant
    NAME4: SERVICE_NAME_COMMAND_TYPE	VALUE4: the operation type that triggers the current broadcast
    NAME5: TARGET_SERVERS_LIST	VALUE5: the list of OBServer nodes that receive the broadcast. These nodes are non-permanently offline and where the units of the tenant are located.
    NAME6: SUCCESS_SERVERS_LIST	VALUE6: the list of OBServer nodes that successfully receive the broadcast

  • CREATE SERVICE

    This event records the service name to be created and the detailed information of the service after it is created. After you execute the ALTER SYSTEM CREATE SERVICE command, the system generates this event.

    Column	Description
    NAME1: SERVICE_NAME_STRING	VALUE1: the service name to be created
    NAME2: CREATED_SERVICE_NAME	VALUE2: the service name information of the created service

• DELETE SERVICE

  When a user tenant is deleted, the system records the following events.

  • DELETE SERVICE

    This event records the information at the time when the command is initiated. After you execute the ALTER SYSTEM DELETE SERVICE command, the system generates this event.

    Column	Description
    NAME1: DELETED_SERVICE_NAME	VALUE1: the service name information of the service to be deleted

• START SERVICE

  When a user tenant is started, the system records the following events.

  • BROADCAST SERVICE NAME

    This event records the content of the broadcast, the list of OBServer nodes that receive the broadcast, and the list of OBServer nodes that successfully receive the broadcast. When you execute the ALTER SYSTEM SERVICE NAME command, the OBServer node that initiates the command broadcasts the current service name of the tenant to all OBServer nodes where the units of the tenant are located.

    Column	Description
    NAME1: EPOCH	VALUE1: the version of the current service name information of the tenant for the current broadcast
    NAME2: TARGET_SERVICE_NAME_ID	VALUE2: the service _name _id of the event that triggers the current broadcast
    NAME3: SERVICE_NAME_LIST	VALUE3: the current service_name of the tenant
    NAME4: SERVICE_NAME_COMMAND_TYPE	VALUE4: the operation type that triggers the current broadcast
    NAME5: TARGET_SERVERS_LIST	VALUE5: the list of OBServer nodes that receive the broadcast. These nodes are non-permanently offline and where the units of the tenant are located.
    NAME6: SUCCESS_SERVERS_LIST	VALUE6: the list of OBServer nodes that successfully receive the broadcast

  • START SERVICE

    This event records the information at the time when the command is initiated and the time when the command is completed. After you execute the ALTER SYSTEM START SERVICE command, the system generates this event.

    Column	Description
    NAME1: SERVICE_NAME_BEFORE	VALUE1: the service name information before the service is started
    NAME2: SERVICE_NAME_AFTER	VALUE2: the service name information after the service is started

• STOP SERVICE

  When a user tenant is stopped, the system records the following events.

  • KILL CONNECTIONS OF SERVICE NAME

    Each OBServer node terminates the connections established through the service name to be stopped and generates a record in the tenant event view. If no connection is established through the service name to be stopped on an OBServer node, this event is not recorded in the table.

    Column	Description
    NAME1: SERVICE_NAME	VALUE1: the service name information of the service to be stopped
    NAME2: KILLED_CONNECTIONS_COUNT	VALUE2: the number of terminated connections
    NAME3: KILLED_CONNECTIONS_LIST	VALUE3: the IDs of the terminated connections

  • BROADCAST SERVICE NAME

    This event records the content of the broadcast, the list of OBServer nodes that receive the broadcast, and the list of OBServer nodes that successfully receive the broadcast. When you execute the ALTER SYSTEM STOP SERVICE command, the OBServer node that initiates the command broadcasts the current service name of the tenant to all OBServer nodes where the units of the tenant are located.

    Column	Description
    NAME1: EPOCH	VALUE1: the version of the current service name information of the tenant for the current broadcast
    NAME2: TARGET_SERVICE_NAME _ID	VALUE2: the service _name _id of the event that triggers the current broadcast
    NAME3: SERVICE_NAME_LIST	VALUE3: the current service_name of the tenant
    NAME4: SERVICE_NAME_COMMAND_TYPE	VALUE4: the operation type that triggers the current broadcast
    NAME5: TARGET_SERVERS_LIST	VALUE5: the list of OBServer nodes that receive the broadcast. These nodes are non-permanently offline and where the units of the tenant are located.
    NAME6: SUCCESS_SERVERS_LIST	VALUE6: the list of OBServer nodes that successfully receive the broadcast

  • STOP SERVICE

    This event records the information at the time when the command is initiated and the time when the command is completed. After you execute the ALTER SYSTEM STOP SERVICE command, the system generates this event.

    Attribute	Attribute value
    NAME1: SERVICE_NAME_BEFORE	VALUE1: Information about the service name before the service is stopped.
    NAME2: SERVICE_NAME_AFTER	VALUE2: Information about the service name after the service is stopped.

DBMS_BALANCE

The DBMS_BALANCE module provides four operations: TRIGGER PARTITION BALANCE, SET BALANCE WEIGHT, CLEAR BALANCE WEIGHT, and CLEAR EXPIRED BALANCE WEIGHT.

• TRIGGER PARTITION BALANCE

  When you execute the DBMS_BALANCE.TRIGGER_PARTITION_BALANCE operation, the system records a TRIGGER PARTITION BALANCE event in the tenant event record table.

  The TRIGGER PARTITION BALANCE event records the specific time when the DBMS_BALANCE.TRIGGER_PARTITION_BALANCE command was executed and the related parameters.

  Attribute	Attribute Value
  NAME1: BALANCE_TIMEOUT_S	VALUE1: The timeout parameter when triggering the balance, in seconds.

• SET BALANCE WEIGHT

  When you execute the DBMS_BALANCE.SET_BALANCE_WEIGHT operation, the system records a SET BALANCE WEIGHT event in the tenant event record table.

  The SET BALANCE WEIGHT event records the specific time when the DBMS_BALANCE.SET_BALANCE_WEIGHT command was executed and the related parameters.

  Attribute	Attribute Value
  NAME1: WEIGHT	VALUE1: The weight of the partition.
  NAME2: DATABASE_NAME	VALUE2: The name of the database to which the partition belongs.
  NAME3: TABLE_NAME	VALUE3: The name of the table to which the partition belongs.
  NAME4: PARTITION_NAME	VALUE4: The name of the partition to which the weight is set.
  NAME5: SUBPARTITION_NAME	VALUE5: The name of the subpartition to which the weight is set.

• CLEAR BALANCE WEIGHT

  When you execute the DBMS_BALANCE.CLEAR_BALANCE_WEIGHT operation, the system records a CLEAR BALANCE WEIGHT event in the tenant event record table.

  The CLEAR BALANCE WEIGHT event records the specific time when the DBMS_BALANCE.CLEAR_BALANCE_WEIGHT command was executed and the related parameters.

  Attribute	Attribute Value
  NAME1: DATABASE_NAME	VALUE1: The name of the database to which the partition belongs.
  NAME2: TABLE_NAME	VALUE2: The name of the table to which the partition belongs.
  NAME3: PARTITION_NAME	VALUE3: The name of the partition to which the weight is cleared.
  NAME4: SUBPARTITION_NAME	VALUE4: The name of the subpartition to which the weight is cleared.

• CLEAR EXPIRED BALANCE WEIGHT

  When the background thread clears the weights of expired partitions, the system records a CLEAR EXPIRED BALANCE WEIGHT event in the tenant event record table.

  The CLEAR EXPIRED BALANCE WEIGHT event records the specific time when the background thread cleared the weights of expired partitions and the related parameters.

  Attribute	Attribute Value
  NAME1: TABLE_NAME	VALUE1: The name of the table to which the weights of expired partitions belong.
  NAME2: PARTITION_NAME	VALUE2: The name of the partition to which the weights of expired partitions belong.
  NAME3: SUBPARTITION_NAME	VALUE3: The name of the subpartition to which the weights of expired partitions belong.

Sample query

Query the historical operation records of the current tenant and display the first record.

obclient [SYS]> SELECT * FROM SYS.DBA_OB_TENANT_EVENT_HISTORY WHERE ROWNUM = 1\G

The query result is as follows:

*************************** 1. row ***************************
 TIMESTAMP: 2023-12-14 14:33:20.321725
    MODULE: TENANT ROLE CHANGE
     EVENT: SWITCHOVER TO STANDBY END
     NAME1: STMT_STR
    VALUE1: ALTER SYSTEM SWITCHOVER TO STANDBY TENANT backup_mysql_tenant
     NAME2: TENANT_INFO
    VALUE2: {tenant_id:1002, tenant_role:"STANDBY", switchover_status:"NORMAL", switchover_epoch:1702535600271677, sync_scn:1702535620070597000, replayable_scn:1702535620070597000, readable_scn:1702535620070597000, recovery_until_scn:4611686018427387903, log_mode:"ARCHIVELOG", max_ls_id:1003}
     NAME3: SWITCHOVER_SCN
    VALUE3: 1702535620070597000
     NAME4: COST_DETAIL
    VALUE4: WAIT_LOG_END: 100190, CHANGE_ACCESS_MODE: 47261, OTHERS: 136839
     NAME5: ALL_LS
    VALUE5: NORMAL: 1, 1001, 1002, 1003
     NAME6: NULL
    VALUE6:
EXTRA_INFO: NULL
    SVR_IP: 100.xx.xx.xx
  SVR_PORT: 13324
  TRACE_ID: Y340C64586BD4-00060C724AEB962B-0-0
 COST_TIME: 284290
  RET_CODE: 0
 ERROR_MSG: NULL
1 row in set

References

• Create a service
• View the status of a service
• Start a service
• Suspend a service
• Delete a service