Consume Service
Overview
The consume service can be used to consume messages from a stream. The Rest Proxy supports multiple datatypes for key and value. Headers are returned as name and list of not supported.
Lifecycle
For every consume call the REST Proxy unloads the SSL context and runs the ACL checks against the stream on which the consume is made.
If access is granted, a consumer will be created internally and cached using the AXUAL-CONSUMER-UUID provided in the HTTP Headers.
The rest of the provided http headers are used to initialize the consumer which then will be reused in subsequent calls (given the same AXUAL-CONSUMER-UUID).
That consumer object remains cached for a period of time that is dictated by a REST Proxy configuration parameter (namely axual.consumer.cache-ttl-ms), which defaults to 6 minutes.
Consumer objects are evicted from the cache after axual.consumer.cache-ttl-ms of inactivity.
API Specification
HTTP Request Structure
End Point |
<baseurl>/stream/{environment}/{stream} |
HTTP Method |
|
Content-Type |
|
Path Variables
Path Variable |
Description |
|
The environment |
|
The stream name as specified in the Self Service definition |
HTTP Headers
Header Name |
Require / Optional |
Description |
|
Required |
The unique consumer instance id used to identify the consumer object for the session |
|
Required |
The application id of the the consumer application as specified in the Self Service |
|
Required |
Contains the type of the key data, this should match with the data used in the stream. Can be |
|
Required |
Contains the type of the value data, this should match with the data used in the stream. Can be |
|
Required |
This controls the offset should be committed on next consume call or immediately after the read for the current consume call. Valid values are |
|
Optional |
The version of the the consumer application |
|
Optional |
The maximum number of messages to be returned for the call. Internally this configuration will set the consumer |
|
Optional |
This controls if the stream should be read from the begin (EARLIEST) or the end(LATEST) if no offset has been found. Defaults to EARLIEST |
|
Optional |
The amount of time to wait for the backend poll to complete. During creation of the backend consumer or rebalance this might result in an empty response. This delay during creation/rebalance should normally not take more than 10 seconds. Default value is 500 |
|
Optional |
Return consumer assigned partition offsets in response. Valid values are TRUE and FALSE. Default value is FALSE |
| The UUID needs to be unique (guaranteed by using a UUID generator) and generated prior to the consumer loop. This way the consumer object created internally is unique to the consume session. |