blueflood-core/src/main/java/com/rackspacecloud/blueflood/io/datastax/DAbstractMetricsRW.java
@Override
    public void insertRollups(List<SingleRollupWriteContext> writeContexts) {

        if (writeContexts.size() == 0) {
            return;
        }

        Timer.Context ctx = Instrumentation.getWriteTimerContext( writeContexts.get( 0 ).getDestinationCF().getName() );
        try {

            BatchStatement batch = new BatchStatement(BatchStatement.Type.UNLOGGED);

            for (SingleRollupWriteContext writeContext : writeContexts) {
                Rollup rollup = writeContext.getRollup();
                Locator locator = writeContext.getLocator();
                Granularity granularity = writeContext.getGranularity();
                int ttl = getTtl(locator, rollup.getRollupType(), granularity);

                // lookup the right writer
                RollupType rollupType = writeContext.getRollup().getRollupType();
                DAbstractMetricIO io = getIO(rollupType.name().toLowerCase(), granularity);

                Statement statement = io.createStatement(locator, writeContext.getTimestamp(), rollup, writeContext.getGranularity(), ttl);
                batch.add(statement);
            }

            Session session = DatastaxIO.getSession();
            session.execute(batch);

        } catch (Exception ex) {
            Instrumentation.markWriteError();
            LOG.error(String.format("error writing locator batch of size %s, granularity %s", writeContexts.size(), writeContexts.get(0).getGranularity()), ex);
        } finally {
            ctx.stop();
        }
    }
@Override
    public void insertRollups(List<SingleRollupWriteContext> writeContexts) {

        if (writeContexts.size() == 0) {
            return;
        }

        Timer.Context ctx = Instrumentation.getWriteTimerContext( writeContexts.get( 0 ).getDestinationCF().getName() );
        try {

            BatchStatement batch = new BatchStatement(BatchStatement.Type.UNLOGGED);

            for (SingleRollupWriteContext writeContext : writeContexts) {
                Rollup rollup = writeContext.getRollup();
                Locator locator = writeContext.getLocator();
                Granularity granularity = writeContext.getGranularity();
                int ttl = getTtl(locator, rollup.getRollupType(), granularity);

                // lookup the right writer
                RollupType rollupType = writeContext.getRollup().getRollupType();
                DAbstractMetricIO io = getIO(rollupType.name().toLowerCase(), granularity);

                Statement statement = io.createStatement(locator, writeContext.getTimestamp(), rollup, writeContext.getGranularity(), ttl);
                batch.add(statement);
            }

            Session session = DatastaxIO.getSession();
            session.execute(batch);

        } catch (Exception ex) {
            Instrumentation.markWriteError();
            LOG.error(String.format("error writing locator batch of size %s, granularity %s", writeContexts.size(), writeContexts.get(0).getGranularity()), ex);
        } finally {
            ctx.stop();
        }
    }
This method inserts a collection of {@link com.rackspacecloud.blueflood.service.SingleRollupWriteContext} objects
to the appropriate Cassandra column family.

It performs the inserts by executing an UNLOGGED BATCH statement.

@param writeContexts

@throws IOException