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java driver (v3.x) throttling for async execution
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| private boolean availableInFlightSlots(Statement st) { | |
| boolean available = false; | |
| Iterator<Host> hostIterator = loadBalancingPolicy.newQueryPlan(session.getLoggedKeyspace(), st); | |
| hostIter: while(hostIterator.hasNext()) { | |
| Host host = hostIterator.next(); | |
| int inFlightQueries = session.getState().getInFlightQueries(host); | |
| switch(loadBalancingPolicy.distance(host)) { | |
| case LOCAL: | |
| if (inFlightQueries < maxInFlightLocal) { | |
| available = true; | |
| break hostIter; | |
| } | |
| break; | |
| case REMOTE: | |
| if (inFlightQueries < maxInFlightRemote) { | |
| available = true; | |
| break hostIter; | |
| } | |
| break; | |
| default: | |
| // IGNORED is something we're not going to write to | |
| break; | |
| } | |
| } | |
| return available; | |
| } | |
| private ResultSetFuture scheduleStatement(Statement st, Scheduler scheduler) { | |
| while(true) { | |
| if(availableInFlightSlots(st)) { | |
| return session.executeAsync(st); | |
| } else { | |
| try { | |
| Thread.sleep(0, 1); | |
| } catch (InterruptedException e) { | |
| // | |
| } | |
| } | |
| } | |
| public ResultSetFuture execute(Statement query) { | |
| return scheduleStatement(query)); | |
| } | |
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