Checking Monitoring Metrics of ClickHouse Replication Table Data Synchronization

Scenarios

In ClickHouse, Replicated*MergeTree tables are used to achieve high availability (HA) and support distributed data storage. These tables can have multiple replicas within the same shard, and data is automatically synchronized between the replicas to maintain data consistency and reliability.

MRS offers a visualized monitoring tool within FusionInsight Manager that helps users manage and track data synchronization. The tool records the synchronization status between replicas.

Notes and Constraints

Currently, you can monitor and query only Replicated*MergeTree tables whose creation statements contain the key word ON CLUSTER.

Replication Table Data Synchronization

MRS 3.2.0-LTS or later:

1. Log in to FusionInsight Manager.

   For details, see Accessing FusionInsight Manager.

2. Choose Cluster > Services > ClickHouse. On the displayed page, click Logical Cluster, and click the target logical cluster name. On the displayed page, select Data Synchronization Status to view the data synchronization status of the current logical cluster.

   You can select By Data Tables and enter a data table name in the search box to filter data tables.

   Table 1 Data synchronization parameters

   Parameter	Description
   Data Tables	Names of Replicated*MergeTree tables.
   Database	Database where the data table is located.
   Shard	ClickHouse shard where the data table is located.
   Status	Data synchronization status. The options are as follows: No data: The table has no data on this shard. Synchronized: The table has data on this shard, and data on multiple replicas of the same shard is the same. Not synchronized: The table has data on this shard, but data on multiple replicas of the same shard is not the same.
   Details	Data synchronization details of the data table on the corresponding ClickHouseServer instance.

For versions earlier than MRS 3.2.0-LTS:

1. Log in to FusionInsight Manager.

   For details, see Accessing FusionInsight Manager.

2. Choose Cluster > Services > ClickHouse. Click Data Synchronization Status to view the data synchronization status of the current cluster.

   You can select By Data Tables and enter a data table name in the search box to filter data tables.

   Table 2 Data synchronization parameters

   Parameter	Description
   Data Tables	Names of Replicated*MergeTree tables.
   Database	Database where the data table is located.
   Shard	ClickHouse shard where the data table is located.
   Status	Data synchronization status. The options are as follows: No data: The table has no data on this shard. Synchronized: The table has data on this shard, and data on multiple replicas of the same shard is the same. Not synchronized: The table has data on this shard, but data on multiple replicas of the same shard is not the same.
   Details	Data synchronization details of the data table on the corresponding ClickHouseServer instance.