Kaffe v1.14.1 Kaffe.Subscriber View Source
Consume messages from a single partition of a single Kafka topic.
Assignments are received from a group consumer member, Kaffe.GroupMember
.
Messages are delegated to Kaffe.Worker
. The worker is expected to cast back
a response, at which time the stored offset will be acked back to Kafka.
The options (ops
) to subscribe/7
may include the beginning offset
using :begin_offset
.
The subscriber reads the following options out of the configuration:
- `max_bytes` - The maximum number of message bytes to receive in a batch
- `min_bytes` - The minimum number of message bytes to receive in a batch
- `max_wait_time` - Maximum number of milliseconds broker will wait for `:min_bytes` of messages
to be collected
- `offset_reset_policy` - The native `auto.offset.reset` option,
either `:reset_to_earliest` or `:reset_to_latest`.
See: https://github.com/klarna/brucke/blob/master/src/brucke_member.erl Also: https://github.com/klarna/brod/blob/master/src/brod_consumer.erl
Link to this section Summary
Functions
Returns a specification to start this module under a supervisor.
Invoked when the server is started. start_link/3
or start/3
will
block until it returns.
Link to this section Functions
child_spec(arg) View Source
Returns a specification to start this module under a supervisor.
See Supervisor
.
commit_offsets(subscriber_pid, topic, partition, generation_id, offset) View Source
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
.