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    Performance Testing:Specify source IP count

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    Performance Testing:Specify source IP count

    Last Updated:Jun 17, 2026

    When a single IP address sends too many requests during stress testing, protection mechanisms may block the traffic. You can increase the number of source IP addresses based on virtual user count or RPS to reduce the likelihood of traffic blocking. The allowed range is displayed on the console page.

    Procedure

    1. Log on to the PTS console, choose Performance Test > Create Scenario, and then click PTS.

    2. Set the number of source IP addresses.

      Important

      • Increasing the number of IP addresses increases your cost. For billing purposes, the billable virtual user count is calculated as Number of IP addresses × 500. You can view the estimated VUM consumption in the stress estimation chart on the right.

        Number of IP addresses: This corresponds to the number of load generators. A single load generator supports a maximum of 500 concurrent virtual users.
        500: For billing purposes, each source IP address counts as 500 virtual users, regardless of the actual concurrency configured for the test. For more information, see pay-as-you-go.

      • If the current IP address limit is insufficient, you can submit a ticket to request a capacity increase.

      For example, if you set Maximum virtual users to 3000, Number of IP addresses to 6, and Total test duration to 10 minutes, the stress estimation chart shows an estimated consumption of 30000 VUM (that is, 6 × 500 × 10 = 30000).

    Causes of stress testing failures

    • SLB limits

      Verify that you have not exceeded the specification or bandwidth limits of your Server Load Balancer (SLB) instance. These limits vary by billing method. If SLB serves as the public entry point for your service and the API uses HTTPS or session persistence, you may receive a 503 error during stress testing. If no corresponding traffic or logs appear on the backend, the SLB instance may be rate-limiting a single source IP address. For a solution, see 503 (Service Unavailable).

    • Anti-DDoS or WAF is active

      Anti-DDoS or Web Application Firewall (WAF) may block stress testing traffic. To resolve this, take one of the following actions:

      Temporarily disable Anti-DDoS or WAF during the stress test. For more information, see Anti-DDoS FAQ Overview.

      Add the PTS User-Agent (UA) to a whitelist to allow stress testing traffic. For more information, see What do I do if PTS stress testing traffic cannot directly access my web application due to security policies?.

    • Using CDN or DCDN

      If your planned test will generate traffic approaching or exceeding your service's peak levels, we recommend that you submit a ticket in advance to report the planned test.

    High load on the load generator cluster

    If monitoring data shows that the load generator cluster is bottlenecked by bandwidth, CPU, or memory, increase the number of source IP addresses to raise the overall capacity of the cluster.