# Temporal SDK metrics reference > For the complete documentation index, see [llms.txt](https://docs.temporal.io/llms.txt). > Any documentation page is available as raw Markdown by appending `.md` to its URL. > Metrics Temporal SDKs emit from Clients and Workers, with each metric's type, tags, and the SDKs that define it. > **ℹī¸ Info:** > > For metrics emitted by [Temporal Cloud](/evaluate/cloud), see [Cloud metrics](/cloud/metrics/openmetrics). > For metrics emitted by a [self-hosted Temporal Service](/temporal-service), see [Temporal Service metrics](/references/service-metrics). > To tune Workers based on these metrics, see [Worker performance](/develop/worker-performance). > The [Temporal SDKs](/encyclopedia/architecture/temporal-sdks) emit metrics from Temporal Client usage and Worker Processes. To set up metrics in your application, see the observability guide for your SDK: [Go](/develop/go/platform/observability#metrics), [Java](/develop/java/platform/observability#metrics), [Python](/develop/python/platform/observability#metrics), [TypeScript](/develop/typescript/platform/observability#metrics), [.NET](/develop/dotnet/platform/observability#metrics), or [Ruby](/develop/ruby/platform/observability#metrics). Only the metrics on this page have guaranteed, defined behavior. Some SDKs emit other metrics. Treat those as deprecated, inconsistent, or experimental. The SDKs add the `temporal_` prefix to every metric before exporting it. Headings on this page omit the prefix. Each metric on this page lists the following: - **Type:** Counter, Gauge, or Histogram. - **Available in:** The SDK that defines the metric. Other SDKs inherit their metrics from one of these: - **Core:** The [Core SDK](/glossary#core-sdk) defines the metrics for the TypeScript, Python, .NET, and Ruby SDKs, in [Worker metrics](https://github.com/temporalio/sdk-rust/blob/main/crates/sdk-core/src/telemetry/metrics.rs) and [Client metrics](https://github.com/temporalio/sdk-rust/blob/main/crates/client/src/metrics.rs). - **Go:** The Go SDK defines the metrics for the Go and PHP SDKs, in [Worker and Client metrics](https://github.com/temporalio/sdk-go/blob/main/internal/common/metrics/constants.go). - **Java:** The Java SDK defines its own metrics, in [Worker metrics](https://github.com/temporalio/sdk-java/blob/main/temporal-sdk/src/main/java/io/temporal/worker/MetricsType.java) and [Client metrics](https://github.com/temporalio/sdk-java/blob/main/temporal-serviceclient/src/main/java/io/temporal/serviceclient/MetricsType.java). - **Tags:** The [tags](/glossary#tag) the SDK attaches to the metric. Prometheus and other OpenMetrics-compatible systems call these labels. > **📝 Note:** > Metric units across SDKs > > The unit for Histogram metrics depends on the SDK: > > - **Core-based SDKs:** Milliseconds by default. > You can configure Core-based SDKs to use seconds instead. > - **Go and Java SDKs:** Seconds. > Each metric may have some combination of the following tags: - `task_queue`: The Task Queue the Worker Entity polls. - `namespace`: The Namespace the Worker is bound to. - `poller_type`: One of the following: - `workflow_task` - `workflow_sticky_task` - `activity_task` - `nexus_task` - `worker_type`: One of the following: - `ActivityWorker` - `WorkflowWorker` - `LocalActivityWorker` - `NexusWorker` - `activity_type`: The name of the Activity Function. - `workflow_type`: The name of the Workflow Function. - `operation`: The RPC method name. Available on Temporal Client gRPC request metrics. - `status_code`: The gRPC status code the Temporal Service returned, in `UPPER_SNAKE_CASE`, such as `NOT_FOUND`. Available on Temporal Client gRPC request failure metrics. - `cause`: The reason the Temporal Service rejected a request as resource exhausted, such as `RESOURCE_EXHAUSTED_CAUSE_RPS_LIMIT`. Available on the resource-exhausted metrics. Not every SDK attaches every tag, and Histogram buckets differ between SDKs. | Metric name | Emitted by | Metric type | Availability | | -------------------------------------------------------------------------------------------- | -------------- | ----------- | -------------- | | [temporal_activity_execution_cancelled](#activity_execution_cancelled) | Worker | Counter | Java | | [temporal_activity_execution_failed](#activity_execution_failed) | Worker | Counter | Core, Go, Java | | [temporal_activity_execution_latency](#activity_execution_latency) | Worker | Histogram | Core, Go, Java | | [temporal_activity_poll_no_task](#activity_poll_no_task) | Worker | Counter | Core, Go, Java | | [temporal_activity_schedule_to_start_latency](#activity_schedule_to_start_latency) | Worker | Histogram | Core, Go, Java | | [temporal_activity_succeed_endtoend_latency](#activity_succeed_endtoend_latency) | Worker | Histogram | Core, Go, Java | | [temporal_activity_task_error](#activity_task_error) | Worker | Counter | Go | | [temporal_corrupted_signals](#corrupted_signals) | Worker | Counter | Go, Java | | [temporal_local_activity_execution_cancelled](#local_activity_execution_cancelled) | Worker | Counter | Core, Go, Java | | [temporal_local_activity_execution_failed](#local_activity_execution_failed) | Worker | Counter | Core, Go, Java | | [temporal_local_activity_execution_latency](#local_activity_execution_latency) | Worker | Histogram | Core, Go, Java | | [temporal_local_activity_succeed_endtoend_latency](#local_activity_succeed_endtoend_latency) | Worker | Histogram | Core, Go, Java | | [temporal_local_activity_total](#local_activity_total) | Worker | Counter | Core, Go, Java | | [temporal_long_request](#long_request) | Service Client | Counter | Core, Go, Java | | [temporal_long_request_failure](#long_request_failure) | Service Client | Counter | Core, Go, Java | | [temporal_long_request_latency](#long_request_latency) | Service Client | Histogram | Core, Go, Java | | [temporal_long_request_resource_exhausted](#long_request_resource_exhausted) | Service Client | Counter | Go | | [temporal_nexus_poll_no_task](#nexus_poll_no_task) | Worker | Counter | Core, Go, Java | | [temporal_nexus_task_schedule_to_start_latency](#nexus_task_schedule_to_start_latency) | Worker | Histogram | Core, Go, Java | | [temporal_nexus_task_execution_failed](#nexus_task_execution_failed) | Worker | Counter | Core, Go, Java | | [temporal_nexus_task_execution_latency](#nexus_task_execution_latency) | Worker | Histogram | Core, Go, Java | | [temporal_nexus_task_endtoend_latency](#nexus_task_endtoend_latency) | Worker | Histogram | Core, Go, Java | | [temporal_num_pollers](#num_pollers) | Worker | Gauge | Core, Go, Java | | [temporal_poller_start](#poller_start) | Worker | Counter | Go, Java | | [temporal_request](#request) | Service Client | Counter | Core, Go, Java | | [temporal_request_failure](#request_failure) | Service Client | Counter | Core, Go, Java | | [temporal_request_latency](#request_latency) | Service Client | Histogram | Core, Go, Java | | [temporal_request_resource_exhausted](#request_resource_exhausted) | Service Client | Counter | Go | | [temporal_resource_slots_cpu_usage](#resource_slots_cpu_usage) | Worker | Gauge | Core, Java | | [temporal_resource_slots_mem_usage](#resource_slots_mem_usage) | Worker | Gauge | Core, Java | | [temporal_sticky_cache_hit](#sticky_cache_hit) | Worker | Counter | Core, Go, Java | | [temporal_sticky_cache_miss](#sticky_cache_miss) | Worker | Counter | Core, Go, Java | | [temporal_sticky_cache_size](#sticky_cache_size) | Worker | Gauge | Core, Go, Java | | [temporal_sticky_cache_total_forced_eviction](#sticky_cache_total_forced_eviction) | Worker | Counter | Core, Go, Java | | [temporal_unregistered_activity_invocation](#unregistered_activity_invocation) | Worker | Counter | Go | | [temporal_worker_start](#worker_start) | Worker | Counter | Core, Go, Java | | [temporal_worker_task_slots_available](#worker_task_slots_available) | Worker | Gauge | Core, Go, Java | | [temporal_worker_task_slots_used](#worker_task_slots_used) | Worker | Gauge | Core, Go, Java | | [temporal_workflow_active_thread_count](#workflow_active_thread_count) | Worker | Gauge | Java | | [temporal_workflow_canceled](#workflow_canceled) | Worker | Counter | Core, Go, Java | | [temporal_workflow_completed](#workflow_completed) | Worker | Counter | Core, Go, Java | | [temporal_workflow_continue_as_new](#workflow_continue_as_new) | Worker | Counter | Core, Go, Java | | [temporal_workflow_endtoend_latency](#workflow_endtoend_latency) | Worker | Histogram | Core, Go, Java | | [temporal_workflow_failed](#workflow_failed) | Worker | Counter | Core, Go, Java | | [temporal_workflow_task_execution_failed](#workflow_task_execution_failed) | Worker | Counter | Core, Go, Java | | [temporal_workflow_task_execution_latency](#workflow_task_execution_latency) | Worker | Histogram | Core, Go, Java | | [temporal_workflow_task_queue_poll_empty](#workflow_task_queue_poll_empty) | Worker | Counter | Core, Go, Java | | [temporal_workflow_task_queue_poll_succeed](#workflow_task_queue_poll_succeed) | Worker | Counter | Core, Go, Java | | [temporal_workflow_task_replay_latency](#workflow_task_replay_latency) | Worker | Histogram | Core, Go, Java | | [temporal_workflow_task_schedule_to_start_latency](#workflow_task_schedule_to_start_latency) | Worker | Histogram | Core, Go, Java | ### `activity_execution_cancelled` An Activity Execution was canceled. - Type: Counter - Available in: Java - Tags: `activity_type`, `namespace`, `task_queue`, `workflow_type` ### `activity_execution_failed` An Activity Execution failed. In the Go and Java SDKs, this metric doesn't count Local Activity failures. For those, see [`local_activity_execution_failed`](#local_activity_execution_failed). - Type: Counter - Available in: Core, Go, Java - Tags: `activity_type`, `namespace`, `task_queue`, `workflow_type`, `failure_reason` Valid values for the `failure_reason` tag: - `PayloadsTooLarge`: A Payload in the Activity Task response exceeded the Namespace size limit, so the Worker failed the Activity Task as retryable before sending it. See [Activity Payloads too large](/troubleshooting/execution-failures#activity-payloads-too-large). - `ActivityError`: The Activity Task failed for any other reason. ### `activity_execution_latency` Time to complete an Activity Execution, from when the Activity Task is generated to when the SDK responds with a success or failure. - Type: Histogram - Available in: Core, Go, Java - Tags: `activity_type`, `namespace`, `task_queue`, `workflow_type` ### `activity_poll_no_task` An Activity Worker's poll for an Activity Task timed out because no Activity Task was available on the Task Queue. - Type: Counter - Available in: Core, Go, Java - Tags: `namespace`, `task_queue` ### `activity_schedule_to_start_latency` The Schedule-To-Start time of an Activity Task. Use this metric to check that Workers pick up Activity Tasks from the Task Queue promptly. To limit this time, set a [Schedule-To-Start Timeout](/encyclopedia/detecting-activity-failures#schedule-to-start-timeout) when you start the Activity Execution. Some SDKs add the `activity_type` and `workflow_type` tags. The value doesn't vary by type, because the type doesn't affect how fast Workers pull tasks from the Task Queue. - Type: Histogram - Available in: Core, Go, Java - Tags: `namespace`, `task_queue` ### `activity_succeed_endtoend_latency` Total time for a successful Activity Execution, from when it's scheduled to when it completes. The SDK doesn't record this metric for Activities that complete asynchronously. - Type: Histogram - Available in: Core, Go, Java - Tags: `activity_type`, `namespace`, `task_queue`, `workflow_type` ### `activity_task_error` An internal error or panic occurred while the Worker handled or ran an Activity Task. - Type: Counter - Available in: Go - Tags: `activity_type`, `namespace`, `task_queue`, `workflow_type` ### `corrupted_signals` The number of Signals whose Payload the Worker couldn't deserialize. - Type: Counter - Available in: Go, Java - Tags: `namespace`, `task_queue`, `workflow_type` ### `local_activity_execution_cancelled` A Local Activity Execution was canceled. - Type: Counter - Available in: Core, Go, Java - Tags: `activity_type`, `namespace`, `task_queue`, `workflow_type` ### `local_activity_execution_failed` A Local Activity Execution failed. - Type: Counter - Available in: Core, Go, Java - Tags: `activity_type`, `namespace`, `task_queue`, `workflow_type`, `failure_reason` Valid values for the `failure_reason` tag: - `timeout`: The Local Activity exceeded its Schedule-To-Close Timeout or Start-To-Close Timeout. - `ActivityError`: The Local Activity failed for any other reason. ### `local_activity_execution_latency` Time to complete a Local Activity Execution, from when the first Activity Task is generated to when the SDK responds that the execution is complete. - Type: Histogram - Available in: Core, Go, Java - Tags: `activity_type`, `namespace`, `task_queue`, `workflow_type` ### `local_activity_succeed_endtoend_latency` Total time for a successful Local Activity Execution, from when it's scheduled to when it completes. - Type: Histogram - Available in: Core, Go, Java - Tags: `activity_type`, `namespace`, `task_queue`, `workflow_type` ### `local_activity_total` The total number of [Local Activity Executions](/local-activity). - Type: Counter - Available in: Core, Go, Java - Tags: `activity_type`, `namespace`, `task_queue`, `workflow_type` ### `long_request` The Temporal Client made a gRPC long-poll request. - Type: Counter - Available in: Core, Go, Java - Tags: `namespace`, `operation` ### `long_request_failure` A gRPC long-poll request from the Temporal Client failed. The `long_request` counter also counts these requests. - Type: Counter - Available in: Core, Go, Java - Tags: `namespace`, `operation`, `status_code` The `status_code` tag holds the gRPC status code the Temporal Service returned. Values match the gRPC status code names in `UPPER_SNAKE_CASE`, such as `NOT_FOUND`, `RESOURCE_EXHAUSTED`, `UNIMPLEMENTED`, and `INTERNAL`. Client options can suppress this tag, so confirm your metrics endpoint includes it before you write queries against it. ### `long_request_latency` Latency of a gRPC long-poll request from the Temporal Client. - Type: Histogram - Available in: Core, Go, Java - Tags: `namespace`, `operation` ### `long_request_resource_exhausted` The Temporal Service rejected a gRPC long-poll request from the Temporal Client as resource exhausted. The `long_request_failure` metric also counts these failures with `status_code=RESOURCE_EXHAUSTED`. This metric adds the reason for the rejection in the `cause` tag. - Type: Counter - Available in: Go - Tags: `namespace`, `operation`, `cause` The `cause` tag holds the reason the Temporal Service rejected the request, such as `RESOURCE_EXHAUSTED_CAUSE_RPS_LIMIT`, `RESOURCE_EXHAUSTED_CAUSE_CONCURRENT_LIMIT`, `RESOURCE_EXHAUSTED_CAUSE_SYSTEM_OVERLOADED`, or `RESOURCE_EXHAUSTED_CAUSE_CIRCUIT_BREAKER_OPEN`. Use this metric instead of `long_request_failure` to investigate throttling, because the fix depends on the cause. ### `nexus_poll_no_task` A Nexus Worker's poll for a Nexus Task timed out because no Nexus Task was available on the Task Queue. - Type: Counter - Available in: Core, Go, Java - Tags: `namespace`, `task_queue` ### `nexus_task_schedule_to_start_latency` The Schedule-To-Start time of a Nexus Task, from when the request reaches the Frontend Service to when the SDK starts processing the task. The `Request-Timeout` header on the request to the Frontend Service limits this time. - Type: Histogram - Available in: Core, Go, Java - Tags: `namespace`, `task_queue` ### `nexus_task_execution_failed` Handling a Nexus Task resulted in an error. This includes errors returned from your handler and unexpected internal errors in the SDK. - Type: Counter - Available in: Core, Go, Java - Tags: `namespace`, `task_queue`, `nexus_service`, `nexus_operation`, `failure_reason` Valid values for the `failure_reason` tag: - `internal_sdk_error`: The SDK hit an unexpected internal error while handling the Nexus Task. This indicates a bug in the SDK. - `handler_error_{TYPE}`: Your handler returned a [predefined handler error](https://github.com/nexus-rpc/api/blob/main/SPEC.md#predefined-handler-errors) from the Nexus specification. If the handler returns an unexpected error, `{TYPE}` is `INTERNAL`. - `timeout`: Your handler didn't return within the request timeout. - `operation_failed`: Your handler reported that the Nexus Operation failed. In Go, this is an `UnsuccessfulOperationError` with a `failed` state. - `operation_canceled`: Your handler reported that the Nexus Operation completed as canceled. In Go, this is an `UnsuccessfulOperationError` with a `canceled` state. ### `nexus_task_execution_latency` Time to complete a Nexus Task, from when the SDK starts processing it to when your handler completes. - Type: Histogram - Available in: Core, Go, Java - Tags: `namespace`, `task_queue`, `nexus_service`, `nexus_operation` ### `nexus_task_endtoend_latency` Total time for a Nexus Task, from when the request reaches the Frontend Service to when the Temporal Service acknowledges the task's completion to the SDK. - Type: Histogram - Available in: Core, Go, Java - Tags: `namespace`, `task_queue`, `nexus_service`, `nexus_operation` ### `num_pollers` The current number of Worker Entities that are polling. - Type: Gauge - Available in: Core, Go, Java - Tags: `namespace`, `poller_type`, `task_queue` ### `poller_start` A Worker Entity started a poller. - Type: Counter - Available in: Go, Java - Tags: `namespace`, `task_queue` ### `request` The Temporal Client made a gRPC request. - Type: Counter - Available in: Core, Go, Java - Tags: `namespace`, `operation` ### `request_failure` A gRPC request from the Temporal Client failed. The `request` counter also counts these requests. - Type: Counter - Available in: Core, Go, Java - Tags: `namespace`, `operation`, `status_code` The `status_code` tag holds the gRPC status code the Temporal Service returned. Values match the gRPC status code names in `UPPER_SNAKE_CASE`, such as `NOT_FOUND`, `RESOURCE_EXHAUSTED`, `UNIMPLEMENTED`, and `INTERNAL`. Client options can suppress this tag, so confirm your metrics endpoint includes it before you write queries against it. ### `request_latency` Latency of a Temporal Client gRPC request. - Type: Histogram - Available in: Core, Go, Java - Tags: `namespace`, `operation` ### `request_resource_exhausted` The Temporal Service rejected a gRPC request from the Temporal Client as resource exhausted. The `request_failure` metric also counts these failures with `status_code=RESOURCE_EXHAUSTED`. This metric adds the reason for the rejection in the `cause` tag. - Type: Counter - Available in: Go - Tags: `namespace`, `operation`, `cause` The `cause` tag holds the reason the Temporal Service rejected the request, such as `RESOURCE_EXHAUSTED_CAUSE_RPS_LIMIT`, `RESOURCE_EXHAUSTED_CAUSE_CONCURRENT_LIMIT`, `RESOURCE_EXHAUSTED_CAUSE_SYSTEM_OVERLOADED`, or `RESOURCE_EXHAUSTED_CAUSE_CIRCUIT_BREAKER_OPEN`. Use this metric instead of `request_failure` to investigate throttling, because the fix depends on the cause. ### `resource_slots_cpu_usage` CPU usage, from 0 to 100, as measured by the resource-based slot tuner. The SDK emits this metric only when the resource-based slot tuner is enabled. - Type: Gauge - Available in: Core, Java ### `resource_slots_mem_usage` Memory usage, from 0 to 100, as measured by the resource-based slot tuner. The SDK emits this metric only when the resource-based slot tuner is enabled. - Type: Gauge - Available in: Core, Java ### `sticky_cache_hit` A Workflow Task found a cached Workflow Execution to run against. - Type: Counter - Available in: Core, Go, Java - Tags: `namespace`, `task_queue` ### `sticky_cache_miss` A Workflow Task didn't find a cached Workflow Execution to run against. - Type: Counter - Available in: Core, Go, Java - Tags: `namespace`, `task_queue` ### `sticky_cache_size` The current number of Workflow Executions in the cache. - Type: Gauge - Available in: Core, Go, Java - Tags: `namespace` (TypeScript, Java), `task_queue` (TypeScript) ### `sticky_cache_total_forced_eviction` The Worker evicted a Workflow Execution from the cache on purpose. - Type: Counter - Available in: Core, Go, Java - Tags: `namespace`, `task_queue` ### `unregistered_activity_invocation` The Worker received an Activity Task for an Activity type that isn't registered with it. - Type: Counter - Available in: Go - Tags: `activity_type`, `namespace`, `task_queue`, `workflow_type` ### `worker_start` A Worker Entity was registered, created, or started. - Type: Counter - Available in: Core, Go, Java - Tags: `namespace`, `task_queue`, `worker_type` ### `worker_task_slots_available` The number of Workflow, Activity, Local Activity, or Nexus Task execution slots currently available. Use the `worker_type` tag to tell the slot types apart. For example, `WorkflowWorker` slots run Workflow Tasks and `ActivityWorker` slots run Activity Tasks. - Type: Gauge - Available in: Core, Go, Java - Tags: `namespace`, `task_queue`, `worker_type` ### `worker_task_slots_used` The number of Workflow, Activity, Local Activity, or Nexus Task execution slots currently in use. Use the `worker_type` tag to tell the slot types apart. For example, `WorkflowWorker` slots run Workflow Tasks and `ActivityWorker` slots run Activity Tasks. - Type: Gauge - Available in: Core, Go, Java - Tags: `namespace`, `task_queue`, `worker_type` ### `workflow_active_thread_count` The number of Workflow threads in the Worker Process. - Type: Gauge - Available in: Java ### `workflow_canceled` A Workflow Execution ended because of a cancellation request. - Type: Counter - Available in: Core, Go, Java - Tags: `namespace`, `task_queue`, `workflow_type` ### `workflow_completed` A Workflow Execution completed successfully. - Type: Counter - Available in: Core, Go, Java - Tags: `namespace`, `task_queue`, `workflow_type` ### `workflow_continue_as_new` A Workflow Execution ended with Continue-As-New. - Type: Counter - Available in: Core, Go, Java - Tags: `namespace`, `task_queue`, `workflow_type` ### `workflow_endtoend_latency` Total time for a single Workflow Run, from when it's scheduled to when it completes. Each retry of a Workflow Execution is a separate Run. - Type: Histogram - Available in: Core, Go, Java - Tags: `namespace`, `task_queue`, `workflow_type` ### `workflow_failed` A Workflow Execution failed. - Type: Counter - Available in: Core, Go, Java - Tags: `namespace`, `task_queue`, `workflow_type` ### `workflow_task_execution_failed` A Workflow Task Execution failed. - Type: Counter - Available in: Core, Go, Java - Tags: `namespace`, `task_queue`, `workflow_type`, `failure_reason` Valid values for the `failure_reason` tag: - `NonDeterminismError`: The Workflow Task failed because of a non-determinism error. - `GrpcMessageTooLarge`: The Workflow Task response exceeded the gRPC message size limit and couldn't be delivered. The Temporal Service terminates the Workflow Execution in response. See [Troubleshoot the BlobSizeLimitError](/troubleshooting/blob-size-limit-error). - `PayloadsTooLarge`: A Payload or Memo in the Workflow Task response exceeded the Namespace size limit, so the Worker failed the Workflow Task as retryable before sending it. See [Troubleshoot the BlobSizeLimitError](/troubleshooting/blob-size-limit-error#payload-size-limit). - `RequestTooLarge`: The whole Workflow Task completion exceeded the Namespace limit on the size of a single request. The Worker failed the Workflow Task instead of sending a request the Temporal Service would reject, and the Temporal Service retries the Workflow Task. See [Request too large](/troubleshooting/execution-failures#request-too-large). - `WorkflowError`: The Workflow Task failed for any other reason. ### `workflow_task_execution_latency` Time to run a Workflow Task Execution. - Type: Histogram - Available in: Core, Go, Java - Tags: `namespace`, `task_queue`, `workflow_type` ### `workflow_task_queue_poll_empty` A Workflow Worker polled a Task Queue and timed out without picking up a Workflow Task. - Type: Counter - Available in: Core, Go, Java - Tags: `namespace`, `task_queue` ### `workflow_task_queue_poll_succeed` A Workflow Worker polled a Task Queue and successfully picked up a Workflow Task. - Type: Counter - Available in: Core, Go, Java - Tags: `namespace`, `task_queue` ### `workflow_task_replay_latency` Time the Worker spends replaying Event History to catch up before running a Workflow Task. - Type: Histogram - Available in: Core, Go, Java - Tags: `namespace`, `task_queue`, `workflow_type` ### `workflow_task_schedule_to_start_latency` The Schedule-To-Start time of a Workflow Task. - Type: Histogram - Available in: Core, Go, Java - Tags: `namespace`, `task_queue`