GBase 8a提供了show datacopymap功能来查询指定的表，在所有的计算节点上是否有不可用的情况，比如节点离线或服务不可用，某些分片有dmlevent,ddlevent,dmlstorageevent等情况。分片状态正常为0，如果不是0，则表示该主机的该分片，当前不可用，22表示服务离线，包括主机离线；32表示dmlstorageevent，16表示有ddlevent, 2表示有dmlevent。总之，只要不是0，后续的访问就不该继续使用该分片。
目录导航
参考
语法
show datacopymap [DBNAME.]tableName其中DBNAME是库名，tablename是表名。
样例
正常状态(0)
dp_state的数值为0，代表该节点，该分片为正常状态。
gbase> show nodes;
+------------+------------+-------+--------------+----------------+--------+-----------+
| Id | ip | name | primary part | duplicate part | status | datastate |
+------------+------------+-------+--------------+----------------+--------+-----------+
| 3389128714 | 10.0.2.202 | node2 | n1 | n2 | online | 0 |
| 3372351498 | 10.0.2.201 | node1 | n2 | n1 | online | 0 |
+------------+------------+-------+--------------+----------------+--------+-----------+
2 rows in set (Elapsed: 00:00:00.00)
gbase> show datacopymap testdb.t3;
+---------+------------+----------+
| dp_name | node_id | dp_state |
+---------+------------+----------+
| n1 | 3389128714 | 0 |
| n1 | 3372351498 | 0 |
| n2 | 3372351498 | 0 |
| n2 | 3389128714 | 0 |
+---------+------------+----------+
4 rows in set (Elapsed: 00:00:00.00)
[gbase@rh6-1 ~]$ gcadmin
CLUSTER STATE: ACTIVE
CLUSTER MODE: NORMAL
=================================================================
| GBASE COORDINATOR CLUSTER INFORMATION |
=================================================================
| NodeName | IpAddress |gcware |gcluster |DataState |
-----------------------------------------------------------------
| coordinator1 | 10.0.2.201 | OPEN | OPEN | 0 |
-----------------------------------------------------------------
=============================================================
| GBASE DATA CLUSTER INFORMATION |
=============================================================
|NodeName | IpAddress |gnode |syncserver |DataState |
-------------------------------------------------------------
| node1 | 10.0.2.201 | OPEN | OPEN | 0 |
-------------------------------------------------------------
| node2 | 10.0.2.202 | OPEN | OPEN | 0 |
-------------------------------------------------------------
服务离线状态(4/22)
202节点数据库服务停了。经测试，OFFLINE 也是这个结果。
gbase> show datacopymap testdb.t3;
+---------+------------+----------+
| dp_name | node_id | dp_state |
+---------+------------+----------+
| n1 | 3389128714 | 22 |
| n1 | 3372351498 | 0 |
| n2 | 3372351498 | 0 |
| n2 | 3389128714 | 22 |
+---------+------------+----------+
4 rows in set (Elapsed: 00:00:00.01)
[gbase@rh6-1 ~]$ gcadmin
CLUSTER STATE: ACTIVE
CLUSTER MODE: NORMAL
=================================================================
| GBASE COORDINATOR CLUSTER INFORMATION |
=================================================================
| NodeName | IpAddress |gcware |gcluster |DataState |
-----------------------------------------------------------------
| coordinator1 | 10.0.2.201 | OPEN | OPEN | 0 |
-----------------------------------------------------------------
=============================================================
| GBASE DATA CLUSTER INFORMATION |
=============================================================
|NodeName | IpAddress |gnode |syncserver |DataState |
-------------------------------------------------------------
| node1 | 10.0.2.201 | OPEN | OPEN | 0 |
-------------------------------------------------------------
| node2 | 10.0.2.202 |CLOSE | CLOSE | 0 |
-------------------------------------------------------------
数据不一致dmlevent(2)
服务正常，但表存在dmlevent.
gbase> show datacopymap testdb.t3;
+---------+------------+----------+
| dp_name | node_id | dp_state |
+---------+------------+----------+
| n1 | 3389128714 | 2 |
| n1 | 3372351498 | 0 |
| n2 | 3372351498 | 0 |
| n2 | 3389128714 | 0 |
+---------+------------+----------+
4 rows in set (Elapsed: 00:00:00.01)
[gbase@rh6-1 ~]$ gcadmin
CLUSTER STATE: ACTIVE
CLUSTER MODE: NORMAL
=================================================================
| GBASE COORDINATOR CLUSTER INFORMATION |
=================================================================
| NodeName | IpAddress |gcware |gcluster |DataState |
-----------------------------------------------------------------
| coordinator1 | 10.0.2.201 | OPEN | OPEN | 0 |
-----------------------------------------------------------------
=============================================================
| GBASE DATA CLUSTER INFORMATION |
=============================================================
|NodeName | IpAddress |gnode |syncserver |DataState |
-------------------------------------------------------------
| node1 | 10.0.2.201 | OPEN | OPEN | 0 |
-------------------------------------------------------------
| node2 | 10.0.2.202 | OPEN | OPEN | 1 |
-------------------------------------------------------------
[gbase@rh6-1 ~]$ gcadmin showdmlevent
Event count:1
Event ID: 21
ObjectName: testdb.t3
Fail Data Copy:
------------------------------------------------------
SegName: n1 SCN: 4456452 NodeIP: 10.0.2.202 FAILURE
服务离线且有dmlevent（6）
gbase> show datacopymap enc.tr;
+---------+------------+----------+
| dp_name | node_id | dp_state |
+---------+------------+----------+
| NULL | 3372351498 | 0 |
| NULL | 3389128714 | 0 |
| NULL | 3405905930 | 6 |
+---------+------------+----------+
3 rows in set (Elapsed: 00:00:00.00)
[gbase@localhost ~]$ gcadmin
CLUSTER STATE: ACTIVE
CLUSTER MODE: NORMAL
=================================================================
| GBASE COORDINATOR CLUSTER INFORMATION |
=================================================================
| NodeName | IpAddress |gcware |gcluster |DataState |
-----------------------------------------------------------------
| coordinator1 | 10.0.2.201 | OPEN | OPEN | 0 |
-----------------------------------------------------------------
| coordinator2 | 10.0.2.202 | OPEN | OPEN | 0 |
-----------------------------------------------------------------
| coordinator3 | 10.0.2.203 | OPEN | OPEN | 0 |
-----------------------------------------------------------------
=============================================================
| GBASE DATA CLUSTER INFORMATION |
=============================================================
|NodeName | IpAddress |gnode |syncserver |DataState |
-------------------------------------------------------------
| node1 | 10.0.2.201 | OPEN | OPEN | 0 |
-------------------------------------------------------------
| node2 | 10.0.2.202 | OPEN | OPEN | 0 |
-------------------------------------------------------------
| node3 | 10.0.2.203 |CLOSE | OPEN | 1 |
-------------------------------------------------------------
[gbase@localhost ~]$ gcadmin showdmlevent
Event count:1
Event ID: 11
ObjectName: enc.tr
Fail Data Copy:
------------------------------------------------------
SCN: 655387 NodeIP: 10.0.2.203 FAILURE
表结构不一致DDL(16)
服务正常，但表有ddlevent.
gbase> show datacopymap testdb.t4;
+---------+------------+----------+
| dp_name | node_id | dp_state |
+---------+------------+----------+
| n1 | 3389128714 | 16 |
| n1 | 3372351498 | 0 |
| n2 | 3372351498 | 0 |
| n2 | 3389128714 | 16 |
+---------+------------+----------+
4 rows in set (Elapsed: 00:00:00.00)
gbase> ^CAborted
[gbase@rh6-1 ~]$ gcadmin
CLUSTER STATE: ACTIVE
CLUSTER MODE: NORMAL
=================================================================
| GBASE COORDINATOR CLUSTER INFORMATION |
=================================================================
| NodeName | IpAddress |gcware |gcluster |DataState |
-----------------------------------------------------------------
| coordinator1 | 10.0.2.201 | OPEN | OPEN | 0 |
-----------------------------------------------------------------
=============================================================
| GBASE DATA CLUSTER INFORMATION |
=============================================================
|NodeName | IpAddress |gnode |syncserver |DataState |
-------------------------------------------------------------
| node1 | 10.0.2.201 | OPEN | OPEN | 0 |
-------------------------------------------------------------
| node2 | 10.0.2.202 | OPEN | OPEN | 1 |
-------------------------------------------------------------
[gbase@rh6-1 ~]$ gcadmin showddlevent
Event count:1
Event ID: 719712
ObjectName: testdb.t4
Fail Node Copy:
------------------------------------------------------
Fail Data Copy:
------------------------------------------------------
SegName: n1 NodeIP: 10.0.2.202 FAILURE
SegName: n2 NodeIP: 10.0.2.202 FAILURE
总结
只要节点数据状态不是0， 那就一定是有故障，包括服务，数据，表结构等方面。