private Collection<SSTableReader> writeSortedContents(File sstableDirectory) {
boolean isBatchLogTable =
cfs.name.equals(SystemKeyspace.BATCHES)
&& cfs.keyspace.getName().equals(SystemKeyspace.NAME);
logger.debug("Writing {}", Memtable.this.toString());
Collection<SSTableReader> ssTables;
try (SSTableTxnWriter writer =
createFlushWriter(
cfs.getSSTablePath(sstableDirectory), columnsCollector.get(), statsCollector.get())) {
boolean trackContention = logger.isTraceEnabled();
int heavilyContendedRowCount = 0;
// (we can't clear out the map as-we-go to free up memory,
// since the memtable is being used for queries in the "pending flush" category)
for (AtomicBTreePartition partition : partitions.values()) {
// Each batchlog partition is a separate entry in the log. And for an entry, we only do 2
// operations: 1) we insert the entry and 2) we delete it. Further, BL data is strictly
// local,
// we don't need to preserve tombstones for repair. So if both operation are in this
// memtable (which will almost always be the case if there is no ongoing failure), we can
// just skip the entry (CASSANDRA-4667).
if (isBatchLogTable && !partition.partitionLevelDeletion().isLive() && partition.hasRows())
continue;
if (trackContention && partition.usePessimisticLocking()) heavilyContendedRowCount++;
if (!partition.isEmpty()) {
try (UnfilteredRowIterator iter = partition.unfilteredIterator()) {
writer.append(iter);
}
}
}
if (writer.getFilePointer() > 0) {
logger.debug(
String.format(
"Completed flushing %s (%s) for commitlog position %s",
writer.getFilename(),
FBUtilities.prettyPrintMemory(writer.getFilePointer()),
commitLogUpperBound));
// sstables should contain non-repaired data.
ssTables = writer.finish(true);
} else {
logger.debug(
"Completed flushing {}; nothing needed to be retained. Commitlog position was {}",
writer.getFilename(),
commitLogUpperBound);
writer.abort();
ssTables = Collections.emptyList();
}
if (heavilyContendedRowCount > 0)
logger.trace(
String.format(
"High update contention in %d/%d partitions of %s ",
heavilyContendedRowCount, partitions.size(), Memtable.this.toString()));
return ssTables;
}
}
