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Temporal Platform limits sheet


This page will be removed in the near future.

For the latest information on the Temporal Cloud limits, see Temporal Clouds limits sheet.

Running into limits can cause unexpected failures. Knowing the limits of Temporal can prevent that.

This page details many of the errors and warnings coded into the Temporal Platform. Errors are hard limits that fail when reached. Warnings are soft limits that produce a warning log on the server side.


These limits apply specifically to each Workflow Execution and do not pertain to the entire Temporal Platform or individual Namespaces.

  • Identifiers: By default, the maximum length for identifiers (such as Workflow Id, Workflow Type, and Task Queue name) is 1000 characters.
    • This is configurable with the limit.maxIDLength dynamic config variable, set to 255 in this SQL example.
    • The character format is UTF-8.
  • gRPC: gRPC has a limit of 4 MB for each message received.
  • Event batch size: The DefaultTransactionSizeLimit limit is 4 MB. This is the largest transaction size allowed for the persistence of Event Histories.
  • Blob size limit for Payloads (including Workflow context and each Workflow and Activity argument and return value; source):
  • History total size limit (leading to a terminated Workflow Execution):
  • History total count limit (leading to a terminated Workflow Execution):
  • Concurrent limit
    • We fail the following action Commands on Temporal Cloud if the concurrent pending count exceeds 2,000:
      • ScheduleActivityTask
      • SignalExternalWorkflowExecution
      • RequestCancelExternalWorkflowExecution
      • StartChildWorkflowExecution
    • As of v1.21, the open source Temporal Cluster has a default limit of 2,000 pending Activities, Child Workflows, Signals, or Workflow cancellation requests, but you can override the limits in the dynamic configuration using these variables:
      • limit.numPendingActivities.error
      • limit.numPendingSignals.error
      • limit.numPendingCancelRequests.error
      • limit.numPendingChildExecutions.error
    • By default, Batch jobs are limited to one job at a time.
  • Custom Search Attributes limits

For details on dynamic configuration keys, see Dynamic configuration reference.

Default limits for Temporal Cloud

The Temporal Cloud service sets default limits for the following aspects:

  • Account level
    • Users: 100
    • Namespaces: 10
    • Prometheus endpoint Retention Period: 1 month
  • Namespace level
    • Actions per second: 200 (with spikes to 400)
    • Certificates: 32-KB payload or 16 certificates, whichever is smaller
    • Concurrent Task pollers: 2,000 (configurable; maximum of 100,000)
    • Custom Search Attributes (maximum per type)
      • bool: 20
      • double: 20
      • datetime: 20
      • int: 20
      • keyword: 20
      • text: 5
    • Retention Period: 30 days (configurable; range of 1—90 days)
    • Number of Signals received per Workflow Execution: 10,000
  • List Filters
    • The ORDER BY operator isn't supported in List Filters in Temporal Cloud. This means that you can't apply custom ordering of Workflows with Cloud Visibility features. Lists of Workflows are still ordered by a default ordering rule. Be aware that this rule might change.

Some of the Temporal Cloud limits mentioned above can be increased by submitting a support ticket. The default values are intended to guard against unintentional resource usage.