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    Cloud Monitor:Process monitoring

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    Cloud Monitor:Process monitoring

    Last Updated:Jul 10, 2026

    Cloud Monitor collects CPU utilization, memory usage, and open file count for active processes on ECS instances and non-Alibaba Cloud hosts. You can add process monitoring to track process counts and configure alert rules.

    Prerequisites

    The Cloud Monitor agent is installed on your Alibaba Cloud ECS instances and non-Alibaba Cloud hosts. Install the Cloud Monitor agent.

    How process metrics are collected

    Cloud Monitor collects CPU utilization, memory usage, and open file count for the top five CPU-consuming processes every minute.

    • CPU utilization and memory usage: Comparable to the Linux top command.

    • Open file count: Comparable to the Linux lsof command.

    Notes on top-five CPU utilization data:

    • CPU utilization can exceed 100% for multi-core processes because the value is summed across all cores.

    • If the top five processes change during the selected time range, all processes that ranked in the top five are listed. Each process shows the timestamp of its most recent top-five appearance.

    • If a process frequently drops out of the top five, its chart data appears sparse. Denser data points indicate more consistent top-five ranking. For example:

      • The Wrapper process does not consistently rank in the top five, so its data points are sparse.wrapper

      • The dense data points for the Java process indicate consistent top-five ranking.

    Why does process monitoring data start from a specific point in time instead of including full historical data?

    Cloud Monitor begins collecting process metrics only after you add a monitoring item for that process. Historical data from before that point is not available, and alert rules do not apply retroactively.

    Add process monitoring

    Monitor the instance count of critical processes to track their operational status.

    For example, if your host runs the following processes:

    • /usr/bin/java -Xmx2300m -Xms2300m org.apache.catalina.startup.Bootstrap

    • /usr/bin/ruby

    • nginx -c /etc/nginx/nginx.conf

    Adding the following six process keywords produces these results:

    Process keyword

    Count

    Result

    ruby

    1

    Matches the process name.

    nginx

    1

    Matches the process name and arguments.

    /usr/bin

    2

    Matches the path (two processes include this path).

    apache.catalina

    1

    Matches part of the arguments.

    nginx.conf

    1

    Matches part of the arguments.

    -c

    1

    Matches part of the arguments.
    Note

    Process keyword matching is case-sensitive. The keyword must exactly match the process name as shown in the operating system. A case mismatch prevents the keyword from matching the target process, which causes metric collection to fail and alert rules not to trigger.

    1. Log on to the Cloud Monitor console.

    2. In the left-side navigation pane, choose Cloud Resource Monitoring > Host Monitoring.

    3. On the Host Monitoring page, click the instance name of the target host or click Monitoring Charts in the Actions column. Then, select the Process Monitoring tab.

    4. At the bottom of the page, expand the Process Count Monitoring panel and click Add Process Monitor in the upper-right corner.

    5. In the Add Process Monitoring panel, enter the process name, click Add, and then click the image icon in the upper-right corner.

      Note

      It may take a few minutes for monitoring data to appear for the newly added process.

    Create an alert rule for a process

    After adding process monitoring, create an alert rule to receive notifications when the process count changes.

    Recommendation: setting the alert threshold for total process count

    The total process count on a Linux host is limited by the kernel parameter /proc/sys/kernel/pid_max. To avoid false positives or missed alerts, follow these guidelines:

    • Set the alert threshold to 70%–80% of the pid_max value to maintain a safety buffer.

    • Run cat /proc/sys/kernel/pid_max to check the current system limit.

    • Alternatively, obtain the actual process count during a stable business period from Cloud Monitor historical data or by running ps -eLf | wc -l, then add 20%–30% as the alert threshold.

    Avoid setting the threshold to a value close to pid_max.

    1. Log on to the Cloud Monitor console.

    2. In the left-side navigation pane, choose Cloud Resource Monitoring > Host Monitoring.

    3. On the Host Monitoring page, click the instance name of the target host or click Monitoring Charts in the Actions column. Then, select the Process Monitoring tab.

    4. Expand the Process Count Monitoring panel. In the target process chart, click the alert icon image in the upper-right corner to open the alert rule panel.

    5. In the Configure Rule Description panel, set a rule name, define the threshold and alert level for the Process / Number of Current Processes metric, and then click OK.

    6. In the Create Alert Rule panel, configure the alert rule parameters and click Confirm.

      Alert rule parameters are described in Create an alert rule.

    7. View the process alert rule.

      1. In the left-side navigation pane, choose Alerts > Alert Rules.

      2. On the Alert Rules page, you can view the alert rules for the process dimension in the Alert Rule column.

    Delete process monitoring

    Note

    Processes added from Application Groups > Group Process can only be deleted from the Group Process page.

    1. Log on to the Cloud Monitor console.

    2. In the left-side navigation pane, choose Cloud Resource Monitoring > Host Monitoring.

    3. On the Host Monitoring page, click the instance name of the target host or click Monitoring Charts in the Actions column. Then, select the Process Monitoring tab.

    4. Expand the Process Count Monitoring panel and click Add Process Monitor in the upper-right corner. This panel lists all currently monitored processes.

    5. In the Add Process Monitoring panel, click Delete in the Actions column for the target process.

    6. In the Delete confirmation dialog box, click OK.

    7. Click the Close icon in the upper-right corner.

    FAQ

    Does Cloud Monitor support viewing the network bandwidth or traffic of a single process (such as Nginx or Java)?

    Cloud Monitor does not support viewing outbound bandwidth or downlink traffic of individual processes over a specified time period. To monitor per-process network traffic, use a third-party tool such as nethogs on the ECS instance.

    How do I monitor the Java thread count?

    Cloud Monitor process monitoring tracks only process counts. You can add java as a process keyword to track running Java processes. Java thread count monitoring is not supported. To monitor Java thread count, use ARMS Application Monitoring.