# Collect information about OBServer nodes in a cluster

# Collect information about OBServer nodes in a cluster

Description

You can query the __all_server system table for the running status of OBServer nodes in a cluster.

Statement

SELECT /*+READ_CONSISTENCY(WEAK),query_timeout(100000000)*/ *
FROM __all_server
WHERE status = "active"
	OR start_service_time = 0
	OR stop_time > 0;

Troubleshooting method

• If the stop_time value in the __all_server system table is not 0 and the status value is active, the observer process is stopped on the OBServer node and cannot provide services.
• After a started OBServer node establishes a heartbeat connection with RootService, the status of the OBServer node is marked as ACTIVE in OceanBase Database.

If you query the __all_server table now, the status of the OBServer node is ACTIVE but the start_service_time value is 0. The details are as follows:

obclient> select svr_ip,status,start_service_time from __all_server;
+----------------+--------+--------------------+
| svr_ip         | status | start_service_time |
+----------------+--------+--------------------+
| xxx.xx.xxx.1 | active |                  0 |
| xxx.xx.xxx.2 | active |   1617702133437712 |
| xxx.xx.xxx.3 | active |   1617702146772849 |
+----------------+--------+--------------------+
3 rows in set (0.00 sec)