AnalyticDB:Disk locking caused by disk usage

Description

An AnalyticDB for PostgreSQL instance locks and becomes read-only when the storage usage of a compute node exceeds a specific threshold. The locking logic depends on the storage capacity of the AnalyticDB for PostgreSQL compute nodes:

• If a compute node has less than 600 GB of storage capacity, the instance locks when the storage usage of any compute node exceeds 90%.

  You can view the maximum storage watermark of an instance in the console. If the Instance Maximum Storage Water Level exceeds 90%, the instance will be locked. To view the Instance Maximum Storage Water Level, see View storage watermark.

• If a compute node has 600 GB or more of storage capacity, the instance locks when the remaining disk space on any compute node drops below 60 GB.

  You can view the disk space of all nodes of the instance in the console. When the remaining disk space of a node is less than 60 GB, the instance is locked. For information about how to view the disk usage of the nodes of an instance, see the View the disk space of nodes section of this topic.

Instances become read-only after disk locking. To prevent business disruptions, you can upgrade instance specifications or add nodes before the disk usage reaches the threshold. For more information, see Change compute node configurations.

View the disk usage of an instance

1. Log on to the AnalyticDB for PostgreSQL console.
2. In the upper-left corner of the console, select a region.
3. Find the instance that you want to manage and click the instance ID.

4. On the Basic Information page, view the storage usage in the Instance Status section.

   • Maximum Compute Node Storage Usage: The storage usage of the compute node with the most data in the instance.

   • Instance Storage Usage: The average storage usage across all compute nodes in the instance.

View the disk space of nodes

1. Log on to the AnalyticDB for PostgreSQL console.
2. In the upper-left corner of the console, select a region.
3. Find the instance that you want to manage and click the instance ID.

4. In the navigation pane on the left, choose Monitoring and Alerts > Node Monitoring.

5. Click the Compute Nodes tab and view the Storage Used (MB) chart.

   Hover over the chart to view the disk space usage of each node at a specific point in time.

Solution

If your AnalyticDB for PostgreSQL instance locks because it exceeds the storage limit, use one of the following methods to unlock it:

• Upgrade node specifications (Recommended)

  You can upgrade the specifications of the instance to add more disk space.

• Increase the number of nodes

  You can add compute nodes to the instance. After this operation, the data of the instance is redistributed across all compute nodes, which may decrease the disk usage to a value lower than the threshold. If your instance remains locked after you add nodes, Submit a ticket.

For more information about how to upgrade instance specifications and increase the number of nodes, see Change compute node configurations.