Transaction-related errors

OceanBase Database executes a transaction request sent from a client and returns the result to the client. If the transaction execution fails or encounters an exception, an error is reported. Common transaction errors are classified into two types: errors that are thrown to the client during transaction execution and errors that are recorded in system logs or internal views. This topic describes frequently used methods for troubleshooting these two types of errors to help you identify common transaction issues.

Troubleshooting methods

To troubleshoot common transaction errors, query the transaction status table and check the system logs.

The GV$OB_TRANSACTION_PARTICIPANTS view displays the context of participants in transactions that are not terminated on the leader and follower nodes. You need to collect the information of all transaction participants to confirm the execution status of the current transaction. The key fields are described as follows:

• TX_TYPE: The value of this field on the leader node is UNDECIDED during transaction execution, and indicates the type of the transaction, such as LOCAL or DISTRIBUTED during transaction commit.

• STATE: the status of the transaction. The value is ACTIVE during transaction execution.

• ACTION: The value of this field on the leader node is START during transaction execution and COMMIT during transaction commit.

The following example displays the information about some transactions that are in execution:

obclient> select * from gv$ob_transaction_participants\G
*************************** 1. row ***************************
       TENANT_ID: 1002
          SVR_IP: 11.xx.xx.xx
        SVR_PORT: 48274
      SESSION_ID: 3221506881
  SCHEDULER_ADDR: "11.xx.xx.xx:48270"
         TX_TYPE: UNDECIDED
           TX_ID: 752
           LS_ID: 1002
    PARTICIPANTS: NULL
 CTX_CREATE_TIME: 2022-09-21 16:28:46.037405
 TX_EXPIRED_TIME: 2022-09-21 16:43:37.804879
           STATE: ACTIVE
          ACTION: START
PENDING_LOG_SIZE: 57
FLUSHED_LOG_SIZE: 0
            ROLE: LEADER
*************************** 2. row ***************************
       TENANT_ID: 1002
          SVR_IP: 11.xx.xx.xx
        SVR_PORT: 48270
      SESSION_ID: 3221506881
  SCHEDULER_ADDR: "11.xx.xx.xx:48270"
         TX_TYPE: UNDECIDED
           TX_ID: 752
           LS_ID: 1001
    PARTICIPANTS: NULL
 CTX_CREATE_TIME: 2022-09-21 16:28:37.804879
 TX_EXPIRED_TIME: 2022-09-21 16:43:37.804879
           STATE: ACTIVE
          ACTION: START
PENDING_LOG_SIZE: 57
FLUSHED_LOG_SIZE: 0
            ROLE: LEADER

If you choose to check the system logs, you can use the trace ID to search for logs within the corresponding period in the log file of the OBServer node. This way, you can view all logs related to the execution of a statement. You can also use the transaction ID to search for all logs related to the transaction.