Kaffe v1.14.1 Kaffe.GroupManager View Source

This is the main process for bootstrapping the full supervision tree to consume a Kafka topic via a subscriber/worker combo per topic per partition as part of a consumer group.

See Kaffe.GroupMemberSupervisor for distinct components.

The process begins by starting the client connection to Kafka. Then group members are created for each of the configured topics.

Note that this module is is not involved in any message processing, rather it's role is to ensure that all of the relevant services are running.

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Functions

Returns a specification to start this module under a supervisor.

List the currently subscribed topics

Start the subscribers and workers to process message sets

Invoked when the server is started. start_link/3 or start/3 will block until it returns.

List of currently subscribed topics.

Dynamically subscribe to topics in addition to the configured topics. Returns the newly subscribed topics. This may not include all values if any are already subscribed to.

Link to this section Functions

Returns a specification to start this module under a supervisor.

See Supervisor.

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handle_call(msg, from, state) View Source

List the currently subscribed topics

Start the subscribers and workers to process message sets

Worker are booted before the subscribers so when the subscribers receive the first messages, we know there will be a worker to do the actual processing work

Invoked when the server is started. start_link/3 or start/3 will block until it returns.

args is the argument term (second argument) passed to start_link/3.

Returning {:ok, state} will cause start_link/3 to return {:ok, pid} and the process to enter its loop.

Returning {:ok, state, timeout} is similar to {:ok, state} except handle_info(:timeout, state) will be called after timeout milliseconds if no messages are received within the timeout.

Returning {:ok, state, :hibernate} is similar to {:ok, state} except the process is hibernated before entering the loop. See c:handle_call/3 for more information on hibernation.

Returning {:ok, state, {:continue, continue}} is similar to {:ok, state} except that immediately after entering the loop the c:handle_continue/2 callback will be invoked with the value continue as first argument.

Returning :ignore will cause start_link/3 to return :ignore and the process will exit normally without entering the loop or calling c:terminate/2. If used when part of a supervision tree the parent supervisor will not fail to start nor immediately try to restart the GenServer. The remainder of the supervision tree will be started and so the GenServer should not be required by other processes. It can be started later with Supervisor.restart_child/2 as the child specification is saved in the parent supervisor. The main use cases for this are:

  • The GenServer is disabled by configuration but might be enabled later.
  • An error occurred and it will be handled by a different mechanism than the Supervisor. Likely this approach involves calling Supervisor.restart_child/2 after a delay to attempt a restart.

Returning {:stop, reason} will cause start_link/3 to return {:error, reason} and the process to exit with reason reason without entering the loop or calling c:terminate/2.

Callback implementation for GenServer.init/1.

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list_subscribed_topics() View Source

List of currently subscribed topics.

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subscribe_to_topics(topics) View Source

Dynamically subscribe to topics in addition to the configured topics. Returns the newly subscribed topics. This may not include all values if any are already subscribed to.