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https://issues.apache.org/jira/browse/PHOENIX-3083?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Loknath Priyatham Teja Singamsetty resolved PHOENIX-3083.
----------------------------------------------------------
Resolution: Invalid
It is always safe and better to have concurrency control at the TimerTask
run(), instead of relying on ScheduledThreadPoolExecutor.
> Avoid additional handling of concurrency control inside timertask of
> BuildIndexScheduleTask when ScheduledThreadPoolExecutor executeAtFixedRate
> does it internally
> ------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
> Key: PHOENIX-3083
> URL: https://issues.apache.org/jira/browse/PHOENIX-3083
> Project: Phoenix
> Issue Type: Improvement
> Affects Versions: 4.8.0, 4.8.1
> Reporter: Loknath Priyatham Teja Singamsetty
> Assignee: Loknath Priyatham Teja Singamsetty
> Priority: Trivial
>
> MetaDataRegionObserver codesnippet where inprogress AtomicInteger is used for
> concurrency control:
> -----------------------------------------------------------------
> /**
> * Task runs periodically to build indexes whose
> INDEX_NEED_PARTIALLY_REBUILD is set true
> *
> */
> public static class BuildIndexScheduleTask extends TimerTask {
> // inProgress is to prevent timer from invoking a new task while
> previous one is still
> // running
> private final static AtomicInteger inProgress = new AtomicInteger(0);
> RegionCoprocessorEnvironment env;
> public BuildIndexScheduleTask(RegionCoprocessorEnvironment env) {
> this.env = env;
> }
> @Override
> public void run() {
> // FIXME: we should replay the data table Put, as doing a partial
> index build would only add
> // the new rows and not delete the previous index value. Also, we
> should restrict the scan
> // to only data within this region (as otherwise *every* region
> will be running this code
> // separately, all updating the same data.
> RegionScanner scanner = null;
> PhoenixConnection conn = null;
> if (inProgress.get() > 0) {
> LOG.debug("New ScheduledBuildIndexTask skipped as there is
> already one running");
> return;
> }
> try {
> inProgress.incrementAndGet();
> ----------------------------------------------------
> JAVADOC:
> --------------
> public ScheduledFuture<?> scheduleAtFixedRate(Runnable command,
> long initialDelay,
> long period,
> TimeUnit unit)
> Description copied from interface: ScheduledExecutorService
> Creates and executes a periodic action that becomes enabled first after the
> given initial delay, and subsequently with the given period; that is
> executions will commence after initialDelay then initialDelay+period, then
> initialDelay + 2 * period, and so on. If any execution of the task encounters
> an exception, subsequent executions are suppressed. Otherwise, the task will
> only terminate via cancellation or termination of the executor. If any
> execution of this task takes longer than its period, then subsequent
> executions may start late, but will not concurrently execute.
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