Overall status of replication
Column description
| Column name | Description |
|---|---|
| restart_xsn | SN reflected by the remote server that is the target of replication, and the starting point for retransmission when the replication is restarted |
| sender | Whether the sender is running or not |
| receiver | Whether the receiver is running or not |
The name of the replication, IP, sender status, and receiver status can also be checked.
Replication sender information
Column description
| Column name | Description |
|---|---|
| rep_name | Name of replication object |
| peer_ip | IP address of the replication target remote server |
| peer_port | Port number of the replication target remote server |
| Status | It is normal when the current state of sender is 1. / STOP(0), RUN(1), RETRY(2) |
| repl_mode | sender's current replication mode / lazy, eager |
| NET_ERROR_FLAG | network 에러 여부로 0이어야 정상이다. / OK(0), ERROR(1) |
| XSN | sender가 마지막으로 송신한 SN(Serial Number/리두로그일련번호)으로 v$repgap의 REP_SN과 동일 |
The IP, port, network error, and status of the replication sender's remote server can also be checked.
Replication receiver information
Column description
| Column name | Description |
|---|---|
| peer_ip | IP address of the remote server as the subject of replication |
| peer_port | Port number of the remote server that is the subject of replication |
| apply_xsn | SN of the remote server currently being reflected by the receiver |
The IP and port of the remote server of the replication receiver can be checked.
Replication gap
Column description
| Column name | Description |
|---|---|
| rep_name | Name of replication |
| rep_gap | The degree of unsynchronization is indicated by the interval between rep_last_sn and rep_sn. (I.e. rep_last_sn-rep_sn) |
If the replication gap is increased by a lot, there are things to check.
- Check the network status (operation, failure, if IP or port is blocked by the firewall, etc.)
- Check the remote requirement status (hardware failure, remote DB shutdown, etc.)
- Check the BULK DML operation
In the above case, the replication gap may increase, so it is necessary to check the above cases.