Alert thresholds

This chapter lists the default thresholds the plug-in ships and how to change them. Topics: 7.1 Default thresholds · 7.2 Changing thresholds

7.1 Default thresholds

The plug-in ships 19 default metric thresholds, listed below, plus 3 availability conditions (the Status column of each target type’s Response metric, which drive the target’s Up/Down state and are not shown here).

Target type	Metric group	Column	Operator	Warning	Critical	Consecutive occurrences
ip_mysql_database_beta	ReplicationReplicaActivity	seconds_behind_source	>	30	300	1
ip_mysql_database_beta	ReplicationReplicaActivity	replica_io_running	=	—	No	1
ip_mysql_database_beta	ReplicationReplicaActivity	replica_sql_running	=	—	false	1
ip_mysql_database_beta	InnodbBufferPool	innodb_bp_hit_rate	<	95	90	1
ip_mysql_database_beta	InnodbTransaction	innodb_trx_history_list_length	>	100000	1000000	1
ip_mysql_database_beta	ConnectionActivity	aborted_connects_delta	>	10	50	1
ip_mysql_database_beta	ThreadsActivity	connection_saturation_pct	>	80	95	1
ip_mysql_database_beta	TableActivity	disk_tmp_table_pct	>	25	50	1
ip_mysql_database_beta	SysSchemaStatus	sys_supported	<	—	1	1
ip_mysql_database_beta	BackupStatus	hours_since_last_success	>	26	50	1
ip_mysql_database_beta	BackupStatus	last_backup_failed	>	—	0	1
ip_mysql_database_beta	BackupStatus	never_succeeded	>	—	0	1
ip_mysql_database_beta	License	licensed	<	—	1	1
ip_mysql_database_beta	License	days_remaining	<	30	7	1
ip_mysql_cluster_beta	GroupMemberStats	count_transactions_remote_in_applier_queue	>	100	1000	1
ip_mysql_cluster_beta	GroupMemberStats	count_transactions_in_queue	>	100	1000	1
ip_mysql_cluster_beta	GrConsensus	avg_consensus_time_us	>	100000	1000000	1
ip_mysql_cluster_beta	BackupSource	source_offline	>	0	—	1
ip_mysql_clusterset_beta	ClusterSetHealth	dr_promotion_ready	<	—	1	2

7.2 Changing thresholds

The shipped values are starting points sized for lab workloads, not tuning. Review each one against your own service levels and change the ones that do not fit.

Thresholds live on the target, and you edit them from Metric and Collection Settings:

1. From the target’s home page, choose the target-type menu → Monitoring → Metric and Collection Settings.
2. Set the View list to All metrics so that columns without a current threshold are listed too.
3. Find the metric group and column — 7.1 gives both names for every shipped threshold, and the metrics reference (6.1) gives them for every other column.
4. Edit Warning Threshold and Critical Threshold on the row, or click the row’s edit icon for the full editor.
5. Set Number of Occurrences if the condition should have to hold for more than one collection before it raises an incident. The shipped thresholds use one occurrence, except dr_promotion_ready, which uses two.
6. Click OK to save. The new value applies from the next collection.

Clearing a threshold field removes the threshold: the column keeps collecting and stops alerting. The same page changes a group’s collection schedule, and can stop a group collecting altogether — use that rather than deleting a target when you want to quiet a metric group.

Confirm what a target is actually carrying:

emcli get_threshold -target_name="mysql84-prod-01" -target_type="ip_mysql_database_beta"

Note: A threshold edited this way is an override on that one target, and applying a monitoring template to the target replaces it with the template’s value. Where a value should hold across a fleet, put it in a monitoring template — Enterprise → Monitoring → Monitoring Templates, created from a MySQL target and applied to a group — rather than editing targets one at a time and having the next template apply undo the work.

↑ MySQL Plug-in documentation