MySQL / MariaDB

The MYSQL layer monitors MySQL and MariaDB servers. It is populated by OAP’s MySQL/MariaDB monitoring, which scrapes a Prometheus-style mysqld-exporter and turns the result into SkyWalking meters — there is no language agent here, the data comes from the exporter.

In Horizon’s sidebar this layer lives under the Databases group and is named MySQL / MariaDB. A monitored cluster is listed as a MySQL cluster and each member server as a Node. This is a metrics-only layer: it enables the Service and Instance scopes and nothing else — there is no endpoint scope, no topology, and no traces or logs tabs.

This page is the operator reference for the bundled MySQL / MariaDB dashboard: what you see on each scope and what each widget means.

The widgets and metrics below are read from the bundled MYSQL template; if an operator has published a customized MYSQL template to OAP, the live dashboard reflects that copy instead. See Layer Dashboard Templates for how the bundled default, your local draft, and the OAP-published copy relate.

Service list

Before opening a cluster, the layer landing page lists every MySQL cluster with four sortable columns, sorted by QPS by default. Each column aggregates the per-node meters across the whole cluster:

  • QPS — queries per second across the cluster (aggregate_labels(meter_mysql_qps,sum)).

  • TPS — transactions per second across the cluster (aggregate_labels(meter_mysql_tps,sum)).

  • Slow QPS — slow queries per second across the cluster (aggregate_labels(meter_mysql_slow_queries_rate,sum)).

  • Conn Errors — connection-error rate, internal rejects plus max-connection rejects summed (aggregate_labels(meter_mysql_connection_errors_internal,sum) + aggregate_labels(meter_mysql_connection_errors_max_connections,sum)).

Service dashboard

The primary drill-down for one selected cluster. Every widget here aggregates across the cluster’s nodes with aggregate_labels(..., sum).

  • QPS — cluster-wide queries per second (aggregate_labels(meter_mysql_qps,sum)).

  • TPS — cluster-wide transactions per second (aggregate_labels(meter_mysql_tps,sum)).

  • Slow Queries / s — cluster-wide slow-query rate (aggregate_labels(meter_mysql_slow_queries_rate,sum)).

  • Connection Errors — two series, internal rejects vs max-connection rejects (aggregate_labels(meter_mysql_connection_errors_internal,sum) and aggregate_labels(meter_mysql_connection_errors_max_connections,sum)).

  • Commands Trend — rows-affected rate per command type: select / insert / update / delete (aggregate_labels(meter_mysql_commands_select_rate,sum), meter_mysql_commands_insert_rate, meter_mysql_commands_update_rate, meter_mysql_commands_delete_rate).

  • Threads — thread counters: connected / running / cached / created (aggregate_labels(meter_mysql_threads_connected,sum), meter_mysql_threads_running, meter_mysql_threads_cached, meter_mysql_threads_created).

  • Slow Statements — the top 20 slowest captured statements across the cluster, in ms, worst-first (top_n(top_n_database_statement, 20, des)). Each row carries the sampled statement text. Shows no data when OAP captured no statements in the window.

Instance dashboard

For one selected Node (a single MySQL/MariaDB server in the cluster). The four top cards are point-in-time configuration / status readings; the rest are per-node time series.

Status cards

  • Uptime — how long the server has been up, in days (latest(meter_mysql_instance_uptime)/3600/24).

  • Max Connections — the server’s configured max_connections ceiling (latest(meter_mysql_instance_max_connections)).

  • InnoDB Buffer Pool — the InnoDB buffer-pool size in MB (latest(meter_mysql_instance_innodb_buffer_pool_size)/1024/1024).

  • Thread Cache Size — the configured thread-cache size (latest(meter_mysql_instance_thread_cache_size)).

Time series

  • QPS / TPS — this node’s queries per second and transactions per second on one chart (meter_mysql_instance_qps, meter_mysql_instance_tps).

  • Slow Queries / s — this node’s slow-query rate (meter_mysql_instance_slow_queries_rate).

  • Commands Trend — rows-affected rate per command type for this node: select / insert / update / delete (meter_mysql_instance_commands_select_rate, meter_mysql_instance_commands_insert_rate, meter_mysql_instance_commands_update_rate, meter_mysql_instance_commands_delete_rate).

  • Threads — this node’s thread counters: connected / running / cached / created (meter_mysql_instance_threads_connected, meter_mysql_instance_threads_running, meter_mysql_instance_threads_cached, meter_mysql_instance_threads_created).

  • Connects — available vs aborted connection rate (meter_mysql_instance_connects_available, meter_mysql_instance_connects_aborted).

  • Connection Errors — internal rejects vs max-connection rejects for this node (meter_mysql_instance_connection_errors_internal, meter_mysql_instance_connection_errors_max_connections).

Requirements

The MySQL / MariaDB dashboard is a pure consumer of what OAP reports — it invents no data, and a widget with no backing data simply reads no data. To populate it, OAP needs MySQL/MariaDB monitoring enabled so it scrapes a mysqld-exporter and produces:

  • Cluster (service-scope) meters — the meter_mysql_* family: QPS / TPS, slow-query rate, connection errors, the per-command rates, and the thread counters. These back the Service list and the Service dashboard.

  • Node (instance-scope) meters — the meter_mysql_instance_* family: uptime, max-connections, InnoDB buffer-pool size, thread-cache size, and the per-node QPS/TPS, slow-query, command, thread, connect, and connection-error series. These back the Instance dashboard.

  • Sampled statements — top_n_database_statement for the Slow Statements list, captured by OAP when slow-statement sampling is configured.

Each metric is queried at its own OAP scope; OAP does not roll a metric up across scopes, so the node-scope meter_mysql_instance_* series are empty until per-node data is reported. For the upstream setup steps — exporter configuration and which OAP rules to enable — see the MySQL/MariaDB monitoring documentation.