SHOW REPLICATION STATUS

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 and SecondaryReplay). 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 the SecondaryReplay 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 cluster

a primary cluster to a secondary cluster

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 cluster-db replications will be reported.
This command can be run on any SingleStore node (see Cluster Management Commands).
If a sync replica is out of sync it will not appear in the output.
This command does not display DR clusters and the primary databases that do not have replicas.
The output of this command depends on the number of leaves in a cluster 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. Possible values are `async replica`, `sync replica`, and `master`.
Database	The name of the database being replicated. The database name is the same on the primary and secondary clusters, except for the `sharding` database which is called `sharding_[hash]` on the secondary cluster.
MasterURI	The URI for the primary database instance. The format is `host:port/database_name`.
Master_State	The state of the primary database instance. Commonly, the master state is `online` but differs during transition periods/errors. See Database States for details.
Master_CommitLSN	Position in the log before which all pages have been committed. All content is committed in the pages that are in the log before this log sequence number (LSN).
Master_HardenedLSN	Position in the log before which all pages have been written to the disk.
Master_ReplayLSN	Position in the log before which all pages have been replayed into memory.
Master_TailLSN	Position in the log before which all pages have been reserved for transactions. The next transaction to reserve space from the log will start writing at this LSN.
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. Possible values are `yes` and `no`.
ReplicaURI	The URI for the secondary database instance. The format is `host:port/database_name`.
ReplicaState	The state of the secondary database instance. Possible values are `replicating` and `replication paused`.
Replica_CommitLSN	Position in the log before which all pages have been committed. It is replicated from the master, and thus is expected to be behind Master_CommitLSN.
Replica_HardenedLSN	Position in the log before which all pages have been written to the disk.
Replica_ReplayLSN	Position in the log before which all pages have been replayed into memory. It is always less than or equal to CommitLSN (in an active workload, it is expected to lag behind CommitLSN by few LSN).
Replica_TailLSN	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 feature is only available in SingleStore Enterprise Edition. SingleStore Enterprise Edition includes 24x7 support and several enterprise-only features for critical deployments. For more information about SingleStore Developer and SingleStore Enterprise, see the SingleStore Editions page.

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 |
+--------+----------+------------+--------------+------------------+--------------------+------------------+----------------+----------------+-----------+------------+--------------------------+---------------+-------------------+---------------------+-------------------+-----------------+-----------------+

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