# Built-in Alert Rules MariaDB Enterprise Manager includes a comprehensive set of pre-configured alert rules to provide production-ready monitoring for your entire database stack out-of-the-box. These alerts are built on the integrated Grafana Alerting engine and are designed to detect common issues across your MariaDB Servers, Galera Clusters, MaxScale instances, and the underlying operating systems. A key feature of these rules is the use of a **"sustained for"** duration. This means a condition must remain true for a specified period (e.g., 3 minutes) before an alert will fire. This prevents alert fatigue from brief, transient spikes and ensures you are only notified of persistent, actionable problems. ## MariaDB Server | Alert name | Description | | --------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **MariadbInstanceDown** | MariaDB instance down for 3 minutes (sustained for 3m). Triggers when the exporter reports the instance as down (`mariadb_up = 0`) **or** when no sample from `mariadb_up` has been received for more than 120 seconds. | | **ReplicaProcessDown** | MariaDB instance has a Replica process Down (sustained for 3m). Triggers when replication is unhealthy: the I/O or SQL thread is stopped, **or** `Seconds_Behind_Master` is missing (replica not reporting progress). | | **ReplicaSecondsBehindPrimary** | MariaDB replica is more than 600s behind primary (sustained for 3m). Triggers when replication lag exceeds 600 seconds. | | **HighUtilizationMaxConnections** | MariaDB instance has high connection utilization (sustained for 5m). Triggers when `Threads_connected` exceeds \~80% of `max_connections`. | | **MariaDBInstanceRestart** | MariaDB instance restarted recently (sustained for 5m). Triggers when server uptime is below 1 hour, indicating a recent restart. | | **MariaDBDeadlockFound** | MariaDB Deadlock found in the last 15m (sustained for 5m). Triggers when the count of InnoDB deadlocks increases compared to 15 minutes ago. | ## Galera Cluster | Alert name | Description | | ----------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **GaleraClusterDown** | Galera instance down for 5 minutes (sustained for 5m). Triggers when the cluster is not in Primary state (`wsrep_cluster_status ≠ 1`) **or** the node is not ready (`wsrep_ready ≠ 1`). | | **GaleraNodeNotReady** | Galera node not ready (state ≠ 4) for 5m (sustained for 5m). Triggers when the node is not in **Synced** state and it’s **not** a temporary DESYNC (desync counter did not change in the last 5 minutes). | | **GaleraInWrongState** | Galera instance is in an unexpected state (sustained for 5m). Triggers when the node’s state comment isn’t one of the normal values (Synced / Donor / Joining / Joined / Waiting for SST). | | **GaleraClusterDonorFallingBehind** | Galera donor lagging (recv queue > 100) for 5m (sustained for 5m). Triggers when a **Donor** node (state=2) accumulates a large receive queue, indicating it’s falling behind replication. | | **GaleraClusterSizeChanged** | Galera cluster size changed in last 15m (sustained for 5m). Triggers when the cluster size **increases** within 15 minutes. | ## MaxScale | Alert name | Description | | ------------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **MaxScaleInstanceDown** | MaxScale down for 3 minutes (sustained for 3m). Triggers when **no recent MaxScale metrics** have been received for more than 120 seconds (e.g., MaxScale down or exporter/scrape pipeline issue). | | **MaxScaleNoPrimary** | MaxScale has no primary for 3 minutes (sustained for 3m). Triggers when MaxScale reports **zero servers with role = Primary/Master**. | ## Node/OS | Alert name | Description | | ---------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **NodeFilesystemSpaceUsage** | Filesystem disk space is above 90% (sustained for 1h). Triggers when disk space used exceeds 90% on a writable filesystem. | | **NodeFilesystemSpaceFillingUp** | Filesystem predicted to run out of space within \~24h (sustained for 1h). Triggers when usage is above 80% **and** the trend (predictive model) indicates free space will reach zero within \~24 hours; excludes read-only filesystems. | | **NodeMemoryHighUtilization** | Instance is running out of memory > 95% (sustained for 15m). Triggers when memory utilization exceeds 95%. | | **NodeCPUHighUtilization** | Instance is running out of CPU > 90% (sustained for 15m). Triggers when CPU utilization exceeds 90% over a 5-minute window. | | **NodeFilesystemAlmostOutOfFiles** | Filesystem has less than 3% inodes left (sustained for 1h). Triggers when available inodes drop below 3% on a writable filesystem. | | **NodeNetworkReceiveErrs** | Network interface has a high receive-error rate (sustained for 1h). Triggers when receive errors exceed **1%** of total received packets over a 2-minute rate window. | | **NodeFileDescriptorLimit** | Kernel is predicted to exhaust file descriptors soon (sustained for 15m). Triggers when allocated file descriptors exceed **70%** of the kernel limit. | | **NodeFileDescriptorLimit** | Kernel is close to exhausting file descriptors (sustained for 15m). Triggers when allocated file descriptors exceed **90%** of the kernel limit. | *This page is: Copyright © 2025 MariaDB. All rights reserved.* {% @marketo/form formId="4316" %}