8d54d2c2b6
Rather than our freeform way of listing response codes in our api-ref, we should be using the os-api-ref extension option to get nicely formatted response code listings. https://docs.openstack.org/os-api-ref/latest/usage.html#rest-status-code Change-Id: I70b5f0c20089d0eaa201ab9d9bbf9ec1464ec636
241 lines
5.8 KiB
PHP
241 lines
5.8 KiB
PHP
===============
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Claims (claims)
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===============
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Claim is a mechanism to mark messages so that other workers will not process
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the same message.
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Claim messages
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==============
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.. rest_method:: POST /v2/queues/{queue_name}/claims
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Claims a set of messages from the specified queue.
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This operation claims a set of messages (up to the value of the ``limit``
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parameter) from oldest to newest and skips any messages that are already
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claimed. If no unclaimed messages are available, the API returns a
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``204 No Content`` message.
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When a client (worker) finishes processing a message, it should delete the
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message before the claim expires to ensure that the message is processed only
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once. As part of the delete operation, workers should specify the claim ID
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(which is best done by simply using the provided href). If workers perform
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these actions, then if a claim simply expires, the server can return an error
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and notify the worker of the race condition. This action gives the worker a
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chance to roll back its own processing of the given message because another
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worker can claim the message and process it.
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The age given for a claim is relative to the server's clock. The claim's age
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is useful for determining how quickly messages are getting processed and
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whether a given message's claim is about to expire.
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When a claim expires, it is released. If the original worker failed to process
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the message, another client worker can then claim the message.
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Note that claim creation is best-effort, meaning the worker may claim and
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return less than the requested number of messages.
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The ``ttl`` attribute specifies how long the server waits before releasing
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the claim. The ttl value must be between 60 and 43200 seconds (12 hours).
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You must include a value for this attribute in your request.
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The ``grace`` attribute specifies the message grace period in seconds. The
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value of ``grace`` value must be between 60 and 43200 seconds (12 hours).
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You must include a value for this attribute in your request. To deal with
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workers that have stopped responding (for up to 1209600 seconds or 14 days,
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including claim lifetime), the server extends the lifetime of claimed messages
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to be at least as long as the lifetime of the claim itself, plus the specified
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grace period. If a claimed message would normally live longer than the claim's
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live period, its expiration is not adjusted.
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Response codes
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--------------
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.. rest_status_code:: success status.yaml
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- 201
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- 204
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.. rest_status_code:: error status.yaml
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- 401
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- 403
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- 404
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- 503
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Request Parameters
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------------------
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.. rest_parameters:: parameters.yaml
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- queue_name: queue_name
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- limit: claim_limit
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- ttl: claim_ttl
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- grace: claim_grace
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**Example Claim Messages: JSON request**
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.. literalinclude:: samples/claim_messages_request.json
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:language: javascript
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Response Parameters
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-------------------
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**Example Claim Messages: JSON response**
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.. literalinclude:: samples/claim_messages_response.json
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:language: javascript
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Query Claim
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===========
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.. rest_method:: GET /v2/queues/{queue_name}/claims/{claim_id}
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Queries the specified claim for the specified queue.
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This operation queries the specified claim for the specified queue. Claims
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with malformed IDs or claims that are not found by ID are ignored.
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Response codes
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--------------
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.. rest_status_code:: success status.yaml
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- 200
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.. rest_status_code:: error status.yaml
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- 401
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- 403
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- 404
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- 503
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Request Parameters
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------------------
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.. rest_parameters:: parameters.yaml
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- queue_name: queue_name
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- claim_id: claim_id
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Response Parameters
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-------------------
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**Example Query Claim: JSON response**
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.. literalinclude:: samples/claim_query_response.json
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:language: javascript
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Update(Renew) Claim
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===================
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.. rest_method:: PATCH /v2/queues/{queue_name}/claims/{claim_id}
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Updates the specified claim for the specified queue.
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This operation updates the specified claim for the specified queue. Claims
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with malformed IDs or claims that are not found by ID are ignored.
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Clients should periodically renew claims during long-running batches of work
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to avoid losing a claim while processing a message. The client can renew a
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claim by issuing a ``PATCH`` command to a specific claim resource and
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including a new TTL for the claim (which can be different from the original
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TTL). The server resets the age of the claim and applies the new TTL.
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Response codes
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--------------
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.. rest_status_code:: success status.yaml
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- 204
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.. rest_status_code:: error status.yaml
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- 401
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- 403
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- 404
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- 503
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Request Parameters
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------------------
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.. rest_parameters:: parameters.yaml
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- queue_name: queue_name
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- claim_id: claim_id
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- ttl: claim_ttl
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- grace: claim_grace
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**Example Update Claim: JSON request**
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.. literalinclude:: samples/claim_update_request.json
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:language: javascript
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This operation does not return a response body.
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Delete(Release) Claim
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=====================
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.. rest_method:: DELETE /v2/queues/{queue_name}/claims/{claim_id}
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Releases the specified claim for the specified queue.
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This operation immediately releases a claim, making any remaining, undeleted)
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messages that are associated with the claim available to other workers. Claims
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with malformed IDs or claims that are not found by ID are ignored.
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This operation is useful when a worker is performing a graceful shutdown,
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fails to process one or more messages, or is taking longer than expected to
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process messages, and wants to make the remainder of the messages available
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to other workers.
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Response codes
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--------------
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.. rest_status_code:: success status.yaml
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- 204
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.. rest_status_code:: error status.yaml
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- 401
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- 403
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- 404
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- 503
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Request Parameters
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------------------
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.. rest_parameters:: parameters.yaml
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- queue_name: queue_name
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- claim_id: claim_id
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This operation does not accept a request body and does not return a response
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body.
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