roger v2.4.1 Roger.Partition View Source
Per-node partition registry
Roger implements multi-tenancy by dividing all its work between different “Partitions”. Each partition is identified by a unique ID. Partitions consist of a list of queues, which are defined by its type (an atom) and a max_workers value which sets the concurrency level. The RabbitMQ queue name is constructed of the partition ID + the queue type.
To spread out the work, partitions can be started in the cluster on multiple nodes. The partition’s queue configuration can be different between nodes - i.e. some node might be able to handle more concurrency than others.
Within the cluster, there is one global process
(Roger.Partition.Global
) which manages the partition’s state. In
it, it manages job’s uniqueness, states of paused queues, et cetera.
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
Reconfigure the given Roger partition
Stop the parition of accepting new jobs so it can finish of the remaining jobs
Start a Roger partition
Stop the given Roger partition
Link to this section Types
queue_def() :: {id :: String.t(), max_workers :: non_neg_integer()}
Link to this section Functions
Returns a specification to start this module under a supervisor.
See Supervisor
.
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
.
Reconfigure the given Roger partition
Use this function to adjust the queues for the partition. The queues argument is complete: any queues that are not mentioned, are stopped and messages in them will no longer be processed on this node.
safe_stop(id :: String.t()) :: :ok | {:error, :not_running}
Stop the parition of accepting new jobs so it can finish of the remaining jobs
Start a Roger partition
Given a unique ID and a list of queues, starts the partition
supervision structure. When the partition has already been
started, this calls reconfigure/2
instead.
Stop the given Roger partition