monitor-a-dm-cluster.md

title	summary	aliases
Data Migration Monitoring Metrics	Learn about the monitoring metrics when you use Data Migration to migrate data.	/docs/tidb-data-migration/dev/monitor-a-dm-cluster/

Data Migration Monitoring Metrics

If your DM cluster is deployed using TiUP, the monitoring system is also deployed at the same time. This document describes the monitoring metrics provided by DM-worker.

Task

In the Grafana dashboard, the default name of DM is DM-task.

overview

Overview contains some monitoring metrics of all the DM-worker and DM-master instances or sources in the currently selected task. The current default alert rule is only for a single DM-worker/DM-master instance/source.

Metric name	Description	Alert	Severity level
task state	The state of subtasks for migration	N/A	N/A
storage capacity	The total storage capacity of the disk occupied by relay logs	N/A	N/A
storage remain	The remaining storage capacity of the disk occupied by relay logs	N/A	N/A
binlog file gap between master and relay	The number of binlog files by which the relay processing unit is behind the upstream master	N/A	N/A
load progress	The percentage of the completed loading process of the load unit. The value is between 0%~100%	N/A	N/A
binlog file gap between master and syncer	The number of binlog files by which the binlog replication unit is behind the upstream master	N/A	N/A
shard lock resolving	Whether the current subtask is waiting for sharding DDL migration. A value greater than 0 means that the current subtask is waiting for sharding DDL migration	N/A	N/A

Operation errors

Metric name	Description	Alert	Severity level
before any operate error	The number of errors before any operation	N/A	N/A
source bound error	The number of errors of data source binding operations	N/A	N/A
start error	The number of errors during the start of a subtask	N/A	N/A
pause error	The number of errors during the pause of a subtask	N/A	N/A
resume error	The number of errors during the resuming of a subtask	N/A	N/A
auto-resume error	The number of errors during the auto-resuming of a subtask	N/A	N/A
update error	The number of errors during the update of a subtask	N/A	N/A
stop error	The number of errors during the stop of a subtask	N/A	N/A

High availability

Metric name	Description	Alert	Severity level
number of dm-masters start leader components per minute	The number of DM-master attempts to enable leader related components per minute	N/A	N/A
number of workers in different state	The number of DM-workers in different states	Some DM-worker(s) has (have) been offline for more than one hour	critical
workers' state	The state of the DM-worker	N/A	N/A
number of worker event error	The number of different types of DM-worker errors	N/A	N/A
shard ddl error per minute	The number of different types of sharding DDL errors per minute	Any sharding DDL error occurs	critical
number of pending shard ddl	The number of pending sharding DDL operations	Any pending sharding DDL operation has existed for more than one hour	critical

Task state

Metric name	Description	Alert	Severity level
task state	The state of subtasks	An alert occurs when the subtask has been in the Paused state for more than 20 minutes	critical

Dump/Load unit

The following metrics show only when task-mode is in the full or all mode.

Metric name	Description	Alert	Severity level
dump progress	The percentage of the completed dumping process of the dump unit. The value range is 0%~100%	N/A	N/A
load progress	The percentage of the completed loading process of the load unit. The value range is 0%~100%	N/A	N/A
checksum progress	The percentage of the completed checksum process after the load unit finishes dumping. The value range is 0%~100%	N/A	N/A
total bytes for load unit	The bytes processed in the parsing, in generating data KV, and in generating index KV stages of the import process by the load unit	N/A	N/A
chunk process duration	The duration of the load unit processing the data source file chunk (in seconds)	N/A	N/A
data file size	The total size of the data files (includes the INSERT INTO statement) in the full data imported by the load unit	N/A	N/A
dump process exits with error	The dump unit encounters an error within the DM-worker and exits	Immediate alerts	critical
load process exits with error	The load unit encounters an error within the DM-worker and exits	Immediate alerts	critical

Binlog replication

The following metrics show only when task-mode is in the incremental or all mode.

Metric name	Description	Alert	Severity level
remaining time to sync	The predicted remaining time it takes for syncer to be completely migrated with the upstream master (in minutes)	N/A	N/A
replicate lag gauge	The latency time it takes to replicate the binlog from upstream to downstream (in seconds)	N/A	N/A
replicate lag histogram	The histogram of replicating the binlog from upstream to downstream (in seconds). Note that due to different statistical mechanisms, the data might be inaccurate	N/A	N/A
process exist with error	The binlog replication unit encounters an error within the DM-worker and exits	Immediate alerts	critical
binlog file gap between master and syncer	The number of binlog files by which the syncer processing unit is behind the upstream master	An alert occurs when the number of binlog files by which the syncer processing unit is behind the upstream master exceeds one (>1) and the condition lasts over 10 minutes	critical
binlog file gap between relay and syncer	The number of binlog files by which syncer is behind relay	An alert occurs when the number of binlog files by which the syncer processing unit is behind the relay processing unit exceeds one (>1) and the condition lasts over 10 minutes	critical
binlog event QPS	The number of binlog events received per unit of time (this number does not include the events that need to be skipped)	N/A	N/A
skipped binlog event QPS	The number of binlog events received per unit of time that need to be skipped	N/A	N/A
read binlog event duration	The duration that the binlog replication unit reads the binlog from the relay log or the upstream MySQL (in seconds)	N/A	N/A
transform binlog event duration	The duration that the binlog replication unit parses and transforms the binlog into SQL statements (in seconds)	N/A	N/A
dispatch binlog event duration	The duration that the binlog replication unit dispatches a binlog event (in seconds)	N/A	N/A
transaction execution latency	The duration that the binlog replication unit executes the transaction to the downstream (in seconds)	N/A	N/A
binlog event size	The size of a binlog event that the binlog replication unit reads from the relay log or the upstream MySQL	N/A	N/A
DML queue remain length	The length of the remaining DML job queue	N/A	N/A
total sqls jobs	The number of newly added jobs per unit of time	N/A	N/A
finished sqls jobs	The number of finished jobs per unit of time	N/A	N/A
statement execution latency	The duration that the binlog replication unit executes the statement to the downstream (in seconds)	N/A	N/A
add job duration	The duration that the binlog replication unit adds a job to the queue (in seconds)	N/A	N/A
DML conflict detect duration	The duration that the binlog replication unit detects the conflict in DML (in seconds)	N/A	N/A
skipped event duration	The duration that the binlog replication unit skips a binlog event (in seconds)	N/A	N/A
unsynced tables	The number of tables that have not received the shard DDL statement in the current subtask	N/A	N/A
shard lock resolving	Whether the current subtask is waiting for the shard DDL lock to be resolved. A value greater than 0 indicates that it is waiting for the shard DDL lock to be resolved	N/A	N/A
ideal QPS	The highest QPS that can be achieved when the running time of DM is 0	N/A	N/A
binlog event row	The number of rows in a binlog event	N/A	N/A
finished transaction total	The number of finished transactions in total	N/A	N/A
replication transaction batch	The number of sql rows in the transaction executed to the downstream	N/A	N/A
flush checkpoints time interval	The time interval for flushing the checkpoints (in seconds)	N/A	N/A

Relay log

Note:

Currently, DM v2.0 does not support enabling the relay log feature.

Metric name	Description	Alert	Severity level
storage capacity	The storage capacity of the disk occupied by the relay log	N/A	N/A
storage remain	The remaining storage capacity of the disk occupied by the relay log	An alert is needed once the value is smaller than 10G	critical
process exits with error	The relay log encounters an error within the DM-worker and exits	Immediate alerts	critical
relay log data corruption	The number of corrupted relay log files	Immediate alerts	emergency
fail to read binlog from master	The number of errors encountered when the relay log reads the binlog from the upstream MySQL	Immediate alerts	critical
fail to write relay log	The number of errors encountered when the relay log writes the binlog to disks	Immediate alerts	critical
binlog file index	The largest index number of relay log files. For example, "value = 1" indicates "relay-log.000001"	N/A	N/A
binlog file gap between master and relay	The number of binlog files in the relay log that are behind the upstream master	An alert occurs when the number of binlog files by which the relay processing unit is behind the upstream master exceeds one (>1) and the condition lasts over 10 minutes	critical
binlog pos	The write offset of the latest relay log file	N/A	N/A
read binlog event duration	The duration that the relay log reads binlog from the upstream MySQL (in seconds)	N/A	N/A
write relay log duration	The duration that the relay log writes binlog into the disks each time (in seconds)	N/A	N/A
binlog event size	The size of a single binlog event that the relay log writes into the disks	N/A	N/A

Instance

In the Grafana dashboard, the default name of an instance is DM-instance.

Relay log

Metric name	Description	Alert	Severity level
storage capacity	The total storage capacity of the disk occupied by the relay log	N/A	N/A
storage remain	The remaining storage capacity within the disk occupied by the relay log	An alert occurs once the value is smaller than 10G	critical
process exits with error	The relay log encounters an error in DM-worker and exits	Immediate alerts	critical
relay log data corruption	The number of corrupted relay logs	Immediate alerts	emergency
fail to read binlog from master	The number of errors encountered when relay log reads the binlog from the upstream MySQL	Immediate alerts	critical
fail to write relay log	The number of errors encountered when the relay log writes the binlog to disks	Immediate alerts	critical
binlog file index	The largest index number of relay log files. For example, "value = 1" indicates "relay-log.000001"	N/A	N/A
binlog file gap between master and relay	The number of binlog files by which the relay processing unit is behind the upstream master	An alert occurs when the number of binlog files by which the relay processing unit is behind the upstream master exceeds one (>1) and the condition lasts over 10 minutes	critical
binlog pos	The write offset of the latest relay log file	N/A	N/A
read binlog duration	The duration that the relay log reads the binlog from the upstream MySQL (in seconds)	N/A	N/A
write relay log duration	The duration that the relay log writes the binlog into the disk each time (in seconds)	N/A	N/A
binlog size	The size of a single binlog event that the relay log writes into the disks	N/A	N/A

Task

Metric name	Description	Alert	Severity level
task state	The state of subtasks for migration	An alert occurs when the subtask has been paused for more than 10 minutes	critical
load progress	The percentage of the completed loading process of the load unit. The value range is 0%~100%	N/A	N/A
binlog file gap between master and syncer	The number of binlog files by which the binlog replication unit is behind the upstream master	N/A	N/A
shard lock resolving	Whether the current subtask is waiting for sharding DDL migration. A value greater than 0 means that the current subtask is waiting for sharding DDL migration	N/A	N/A