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https://issues.apache.org/jira/browse/HADOOP-10282?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Chris Li updated HADOOP-10282:
------------------------------
Description:
The FairCallQueue ensures quality of service by altering the order of RPC calls
internally.
It consists of three parts:
1. a Scheduler (`HistoryRpcScheduler` is provided) which provides a priority
number from 0 to N (0 being highest priority)
2. a Multi-level queue (residing in `FairCallQueue`) which provides a way to
keep calls in priority order internally
3. a Multiplexer (`WeightedRoundRobinMultiplexer` is provided) which provides
logic to control which queue to take from
Currently the Mux and Scheduler are not pluggable, but they probably should be
(up for discussion).
This is how it is used:
// Production
1. Call is created and given to the CallQueueManager
2. CallQueueManager requests a `put(T call)` into the `FairCallQueue` which
implements `BlockingQueue`
3. `FairCallQueue` asks its scheduler for a scheduling decision, which is an
integer e.g. 12
4. `FairCallQueue` inserts Call into the 12th queue: `queues.get(12).put(call)`
// Consumption
1. CallQueueManager requests `take()` or `poll()` on FairCallQueue
2. `FairCallQueue` asks its multiplexer for which queue to draw from, which
will also be an integer e.g. 2
3. `FairCallQueue` draws from this queue if it has an available call (or tries
other queues if it is empty)
Additional information is available in the linked JIRAs regarding the Scheduler
and Multiplexer's roles.
> Create a FairCallQueue: a multi-level call queue which schedules incoming
> calls and multiplexes outgoing calls
> --------------------------------------------------------------------------------------------------------------
>
> Key: HADOOP-10282
> URL: https://issues.apache.org/jira/browse/HADOOP-10282
> Project: Hadoop Common
> Issue Type: Sub-task
> Reporter: Chris Li
> Attachments: HADOOP-10282.patch
>
>
> The FairCallQueue ensures quality of service by altering the order of RPC
> calls internally.
> It consists of three parts:
> 1. a Scheduler (`HistoryRpcScheduler` is provided) which provides a priority
> number from 0 to N (0 being highest priority)
> 2. a Multi-level queue (residing in `FairCallQueue`) which provides a way to
> keep calls in priority order internally
> 3. a Multiplexer (`WeightedRoundRobinMultiplexer` is provided) which provides
> logic to control which queue to take from
> Currently the Mux and Scheduler are not pluggable, but they probably should
> be (up for discussion).
> This is how it is used:
> // Production
> 1. Call is created and given to the CallQueueManager
> 2. CallQueueManager requests a `put(T call)` into the `FairCallQueue` which
> implements `BlockingQueue`
> 3. `FairCallQueue` asks its scheduler for a scheduling decision, which is an
> integer e.g. 12
> 4. `FairCallQueue` inserts Call into the 12th queue:
> `queues.get(12).put(call)`
> // Consumption
> 1. CallQueueManager requests `take()` or `poll()` on FairCallQueue
> 2. `FairCallQueue` asks its multiplexer for which queue to draw from, which
> will also be an integer e.g. 2
> 3. `FairCallQueue` draws from this queue if it has an available call (or
> tries other queues if it is empty)
> Additional information is available in the linked JIRAs regarding the
> Scheduler and Multiplexer's roles.
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