Review Persistent Disk Asynchronous Replication performance

This document describes how to view performance metrics for Persistent Disk Asynchronous Replication (PD Async Replication).

To learn more about PD Async Replication, see About Persistent Disk Asynchronous Replication.

Metrics

The following Persistent Disk Asynchronous Replication metrics are available in Cloud Monitoring:

Metric Description
Async replication sent bytes count
(disk/async_replication/sent_bytes_count)
 The delta number of bytes sent through the cross-region network.
Async replication time since last replication
(disk/async_replication/time_since_last_replication)
 The number of seconds since the last replication was done, also known as the recovery point objective (RPO).

Monitor sent byte counts

Use the Async replication sent bytes count metric to graph the average number of byte sent, sampled every minute. The number of sent bytes represents the data your workload writes to block storage, which affects the speed of replication.

  1. In the Google Cloud console, go to the Cloud Monitoring > Metrics Explorer page.

    Go to the Metrics Explorer page

  2. In the Select a metric section, click the Metric menu.

  3. Select Disk (disk).

  4. Select the Disk active metric category list, and then select Async replication sent bytes count (disk/async_replication/sent_bytes_count).

  5. Click Apply.

  6. In the Transform menu, select one of the following:

    • To view the total number of sent bytes, select None.
    • To view the number of bytes sent per second, select Rate.

  7. In the Filters section, do the following:

    1. Click Add filter.
    2. Click inside the Label box to view the list of available labels. Under the heading Resource labels, select project_id. Leave the Comparison value set to = (equals). In the Value field, type or select your project ID. Click Done.
    3. Click Add filter.
    4. In the Label box, select disk_id. Leave the Comparison value set to = (equals). In the Value field, type or select the ID of the primary disk that is replicating.
    5. Click Done.

  8. Click More options.

  9. In the Alignment function menu select an alignment function. The Mean alignment function shows the average number of bytes sent per minute, while the Max alignment function shows the highest number of bytes sent per minute.

  10. In the Min alignment period menu, select an alignment period. The alignment period must be at least one minute.

Monitor RPO

Use the Async replication time since last replication metric to graph the number of seconds since the last replication was done (RPO).

  1. In the Google Cloud console, go to the Cloud Monitoring > Metrics Explorer page.

    Go to the Metrics Explorer page

  2. On the Metrics Explorer page, click Add query.

  3. In the Select a metric section, click the Metric menu.

  4. Select Disk (disk).

  5. Select the Disk active metric category list, and then select Async replication time since last replication (disk/async_replication/time_since_last_replication).

  6. Click Apply.

  7. In the Filters section, add filters for your project ID and disk ID:

    1. Click Add filter.
    2. Click inside the Label box to view the list of available labels. Under the heading Resource labels, select project_id. Leave the Comparison value set to = (equals). In the Value field, type or select your project ID. Click Done.
    3. Click Add filter.
    4. In the Label box, select disk_id. Leave the Comparison value set to = (equals). In the Value field, type or select the ID of the primary disk that is replicating.
    5. Click Done.

  8. Click More options.

  9. In the Alignment function menu, select an alignment function. The Mean alignment function shows the average number of seconds since the last replication was done , while the Max alignment function shows the highest number of seconds since the last replication was done .

  10. In the Min alignment period menu, select the select an alignment period. The alignment period must be at least one minute.

  11. Optional: Save the chart.

What's next