You can view the following Asynchronous Replication metrics 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.
In the Google Cloud console, go to the
Cloud Monitoring > Metrics Explorer page.
In the Select a metric section, click the Metric menu.
Select Disk (disk).
Select the Disk active metric category list, and then select
Async replication sent bytes count
(disk/async_replication/sent_bytes_count).
Click Apply.
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.
In the Filters section, do the following:
Click Add filter.
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.
Click Add filter.
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.
Click Done.
Click More options.
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.
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).
In the Google Cloud console, go to the
Cloud Monitoring > Metrics Explorer page.
In the Select a metric section, click the Metric menu.
Select Disk (disk).
Select the Disk active metric category list, and then select
Async replication time since last replication
(disk/async_replication/time_since_last_replication).
Click Apply.
In the Filters section, add filters for your project ID and disk ID:
Click Add filter.
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.
Click Add filter.
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.
Click Done.
Click More options.
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 .
In the Min alignment period menu, select the select an alignment
period. The alignment period must be at least one minute.
Optional: Save the chart.
What's next
Learn how to customize Asynchronous Replication chats with
Metrics Explorer.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-26 UTC."],[[["\u003cp\u003eThis document provides instructions on how to view performance metrics for Persistent Disk Asynchronous Replication using Cloud Monitoring.\u003c/p\u003e\n"],["\u003cp\u003eYou can monitor the \u003ccode\u003eAsync replication sent bytes count\u003c/code\u003e metric to track the number of bytes sent through the cross-region network, which affects replication speed.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eAsync replication time since last replication\u003c/code\u003e metric allows you to monitor the Recovery Point Objective (RPO) by tracking the time in seconds since the last replication.\u003c/p\u003e\n"],["\u003cp\u003eBoth metrics require you to filter by project ID and disk ID within the Cloud Monitoring Metrics Explorer to view relevant data.\u003c/p\u003e\n"],["\u003cp\u003eThe content includes step-by-step instructions on how to set up the needed filters and alignement functions within the Metrics explorer to monitor both sent byte count and the RPO.\u003c/p\u003e\n"]]],[],null,["*** ** * ** ***\n\nThis document describes how to view performance metrics for\nAsynchronous Replication.\n\nTo learn more about Asynchronous Replication, see\n[About Asynchronous Replication](/compute/docs/disks/async-pd/about#performance).\n\nMetrics\n\nYou can view the following Asynchronous Replication metrics in\n[Cloud Monitoring](/monitoring/docs/monitoring-overview):\n\n| Metric | Description |\n|----------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------|\n| **Async replication sent bytes count** `(disk/async_replication/sent_bytes_count)` | The delta number of bytes sent through the cross-region network. |\n| **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). |\n\nMonitor sent byte counts\n\nUse the **Async replication sent bytes count** metric to graph the average\nnumber of byte sent, sampled every minute. The number of sent bytes represents\nthe data your workload writes to block storage, which affects the speed of\nreplication.\n\n1. In the Google Cloud console, go to the\n **Cloud Monitoring \\\u003e Metrics Explorer** page.\n\n [Go to the Metrics Explorer page](https://console.cloud.google.com/monitoring/metrics-explorer)\n2. In the **Select a metric** section, click the **Metric** menu.\n\n3. Select **Disk** (`disk`).\n\n4. Select the **Disk** active metric category list, and then select\n **Async replication sent bytes count**\n (`disk/async_replication/sent_bytes_count`).\n\n5. Click **Apply**.\n\n6. In the **Transform** menu, select one of the following:\n\n - To view the total number of sent bytes, select **None**.\n - To view the number of bytes sent per second, select **Rate**.\n7. In the **Filters** section, do the following:\n\n 1. Click **Add filter**.\n 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**.\n 3. Click **Add filter**.\n 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.\n 5. Click **Done**.\n8. Click **More options**.\n\n9. In the **Alignment function** menu select an alignment function. The\n **Mean** alignment function shows the average number of bytes sent per minute,\n while the **Max** alignment function shows the highest number of bytes sent\n per minute.\n\n10. In the **Min alignment period** menu, select an alignment\n period. The alignment period must be at least one minute.\n\nMonitor RPO\n\nUse the **Async replication time since last replication** metric to graph the\nnumber of seconds since the last replication was done (RPO).\n\n1. In the Google Cloud console, go to the\n **Cloud Monitoring \\\u003e Metrics Explorer** page.\n\n [Go to the Metrics Explorer page](https://console.cloud.google.com/monitoring/metrics-explorer)\n2. On the **Metrics Explorer** page, click **Add query**.\n\n3. In the **Select a metric** section, click the **Metric** menu.\n\n4. Select **Disk** (`disk`).\n\n5. Select the **Disk** active metric category list, and then select\n **Async replication time since last replication**\n (`disk/async_replication/time_since_last_replication`).\n\n6. Click **Apply**.\n\n7. In the **Filters** section, add filters for your project ID and disk ID:\n\n 1. Click **Add filter**.\n 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**.\n 3. Click **Add filter**.\n 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.\n 5. Click **Done**.\n8. Click **More options**.\n\n9. In the **Alignment function** menu, select an alignment function. The\n **Mean** alignment function shows the average number of seconds since the last\n replication was done , while the **Max** alignment function shows the highest\n number of seconds since the last replication was done .\n\n10. In the **Min alignment period** menu, select the select an alignment\n period. The alignment period must be at least one minute.\n\n11. Optional: Save the chart.\n\nWhat's next\n\n- Learn how to customize Asynchronous Replication chats with [Metrics Explorer](/monitoring/charts/metrics-explorer).\n- Learn more about [Asynchronous Replication](/compute/docs/disks/async-pd/about)."]]