SHOW REPLICATION STATUS
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Shows the list of all connections between the replication master and secondary databases.
Syntax
SHOW REPLICATION STATUS
Remarks
-
The URI identifies the database as
<host>:<port>/<dbName>
. -
Log position is the position in the transactional log formatted as
<LogFileId>:<ByteOffsetInLogFile>
. -
Each database in replicating mode has two background threads (
SecondaryNetwork
andSecondaryReplay
).The state and position of both threads are displayed per-database. The SecondaryNetwork
thread downloads the necessary snapshot files and transaction logs from the primary database and theSecondaryReplay
thread reads transactions from these files and commits them to memory. -
A row in the result table represents a replication.
It could be a replication from: master aggregator to child aggregator
master partition to a replica partition in workspace
a primary workspace to a secondary workspace
It also depends on the node where a user runs this command.
If this command is run on a leaf node, replications from one partition to another will be reported. If it is run in a master aggregator, then the db replications and workspace-db replications will be reported. -
If a sync replica is out of sync it will not appear in the output.
-
This command does not display DR workspaces and the primary databases that do not have replicas.
-
The output of this command depends on the number of leaves in a workspace as explained Replication Distribution Tree.
-
Refer to the Permission Matrix for the required permission.
Output
Column |
Explanation |
---|---|
Role |
The replication role of the local database copy. |
Database |
The name of the database being replicated. |
MasterURI |
The URI for the primary database instance. |
Master_ |
The state of the primary database instance. |
Master_ |
Position in the log before which all pages have been committed. |
Master_ |
Position in the log before which all pages have been written to the disk. |
Master_ |
Position in the log before which all pages have been replayed into memory. |
Master_ |
Position in the log before which all pages have been reserved for transactions. |
MasterCommits |
The number of transactions committed on the primary database instance. |
Connected |
The current state of the connection between master and replica instances of the database. |
ReplicaURI |
The URI for the secondary database instance. |
ReplicaState |
The state of the secondary database instance. |
Replica_ |
Position in the log before which all pages have been committed. |
Replica_ |
Position in the log before which all pages have been written to the disk. |
Replica_ |
Position in the log before which all pages have been replayed into memory. |
Replica_ |
All pages that have been received from the master is below this LSN. |
ReplicaCommits |
The number of transactions committed on the secondary database instance. |
Note
This SingleStore Helios feature is only available in SingleStore Helios Enterprise Edition.
Example
SHOW REPLICATION STATUS;
+--------+----------+------------+--------------+------------------+--------------------+------------------+----------------+----------------+-----------+------------+--------------------------+---------------+-------------------+---------------------+-------------------+-----------------+-----------------+
| Role | Database | Master_URI | Master_State | Master_CommitLSN | Master_HardenedLSN | Master_ReplayLSN | Master_TailLSN | Master_Commits | Connected | Throttling | Replica_URI | Replica_State | Replica_CommitLSN | Replica_HardenedLSN | Replica_ReplayLSN | Replica_TailLSN | Replica_Commits |
+--------+----------+------------+--------------+------------------+--------------------+------------------+----------------+----------------+-----------+------------+--------------------------+---------------+-------------------+---------------------+-------------------+-----------------+-----------------+
| master | cluster | NULL | online | 0:239 | 0:239 | 0:233 | 0:239 | 32 | yes | no | 127.0.0.1:3307/cluster | replicating | 0:238 | 0:239 | 0:238 | 0:239 | 30 |
| master | trades | NULL | online | 0:4294967341 | 0:4294967341 | 0:4294967339 | 0:4294967341 | 39 | yes | no | 127.0.0.1:3307/trades | replicating | 0:4294967340 | 0:4294967341 | 0:4294967340 | 0:4294967341 | 38 |
+--------+----------+------------+--------------+------------------+--------------------+------------------+----------------+----------------+-----------+------------+--------------------------+---------------+-------------------+---------------------+-------------------+-----------------+-----------------+
Last modified: August 4, 2023