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.
Link to this section Summary
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
child_spec(arg) View Source
Returns a specification to start this module under a supervisor.
See Supervisor
.
handle_call(msg, from, state) View Source
List the currently subscribed topics
handle_cast(msg, state) View Source
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
init(list) View Source
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 callingSupervisor.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
.
list_subscribed_topics() View Source
List of currently subscribed topics.
start_link() View Source
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.