Repository: cassandra Updated Branches: refs/heads/cassandra-2.1 6e6863d4d -> 1e57bd155
Track liveRatio per-memtable, not per-CF patch by Aleksey Yeschenko; reviewed by Jonathan Ellis for CASSANDRA-6945 Project: http://git-wip-us.apache.org/repos/asf/cassandra/repo Commit: http://git-wip-us.apache.org/repos/asf/cassandra/commit/47bbfe35 Tree: http://git-wip-us.apache.org/repos/asf/cassandra/tree/47bbfe35 Diff: http://git-wip-us.apache.org/repos/asf/cassandra/diff/47bbfe35 Branch: refs/heads/cassandra-2.1 Commit: 47bbfe35afd750ef110311725f6b2824a91552fd Parents: 180bb75 Author: Aleksey Yeschenko <alek...@apache.org> Authored: Sat Mar 29 00:36:28 2014 +0300 Committer: Aleksey Yeschenko <alek...@apache.org> Committed: Sat Mar 29 00:36:28 2014 +0300 ---------------------------------------------------------------------- CHANGES.txt | 1 + .../apache/cassandra/db/ColumnFamilyStore.java | 21 +------ .../org/apache/cassandra/db/DataTracker.java | 7 +-- src/java/org/apache/cassandra/db/Memtable.java | 58 +++++++++++++++----- 4 files changed, 50 insertions(+), 37 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/cassandra/blob/47bbfe35/CHANGES.txt ---------------------------------------------------------------------- diff --git a/CHANGES.txt b/CHANGES.txt index 399cb01..e9dca70 100644 --- a/CHANGES.txt +++ b/CHANGES.txt @@ -35,6 +35,7 @@ (CASSANDRA-6867) * Add CqlRecordReader using native pagination (CASSANDRA-6311) * Add QueryHandler interface (CASSANDRA-6659) + * Track liveRatio per-memtable, not per-CF (CASSANDRA-6945) Merged from 1.2: * Add UNLOGGED, COUNTER options to BATCH documentation (CASSANDRA-6816) * add extra SSL cipher suites (CASSANDRA-6613) http://git-wip-us.apache.org/repos/asf/cassandra/blob/47bbfe35/src/java/org/apache/cassandra/db/ColumnFamilyStore.java ---------------------------------------------------------------------- diff --git a/src/java/org/apache/cassandra/db/ColumnFamilyStore.java b/src/java/org/apache/cassandra/db/ColumnFamilyStore.java index b58329e..792c155 100644 --- a/src/java/org/apache/cassandra/db/ColumnFamilyStore.java +++ b/src/java/org/apache/cassandra/db/ColumnFamilyStore.java @@ -25,7 +25,6 @@ import java.nio.ByteBuffer; import java.util.*; import java.util.concurrent.*; import java.util.concurrent.atomic.AtomicInteger; -import java.util.concurrent.atomic.AtomicLong; import java.util.regex.Pattern; import javax.management.*; @@ -105,11 +104,6 @@ public class ColumnFamilyStore implements ColumnFamilyStoreMBean public final Directories directories; - /** ratio of in-memory memtable size, to serialized size */ - volatile double liveRatio = 10.0; // reasonable default until we compute what it is based on actual data - /** ops count last time we computed liveRatio */ - private final AtomicLong liveRatioComputedAt = new AtomicLong(32); - public final ColumnFamilyMetrics metric; public volatile long sampleLatencyNanos; @@ -899,20 +893,7 @@ public class ColumnFamilyStore implements ColumnFamilyStoreMBean mt.put(key, columnFamily, indexer); maybeUpdateRowCache(key); metric.writeLatency.addNano(System.nanoTime() - start); - - // recompute liveRatio, if we have doubled the number of ops since last calculated - while (true) - { - long last = liveRatioComputedAt.get(); - long operations = metric.writeLatency.latency.count(); - if (operations < 2 * last) - break; - if (liveRatioComputedAt.compareAndSet(last, operations)) - { - logger.debug("computing liveRatio of {} at {} ops", this, operations); - mt.updateLiveRatio(); - } - } + mt.maybeUpdateLiveRatio(); } /** http://git-wip-us.apache.org/repos/asf/cassandra/blob/47bbfe35/src/java/org/apache/cassandra/db/DataTracker.java ---------------------------------------------------------------------- diff --git a/src/java/org/apache/cassandra/db/DataTracker.java b/src/java/org/apache/cassandra/db/DataTracker.java index a1de8e5..a9eef98 100644 --- a/src/java/org/apache/cassandra/db/DataTracker.java +++ b/src/java/org/apache/cassandra/db/DataTracker.java @@ -30,7 +30,6 @@ import org.slf4j.LoggerFactory; import org.apache.cassandra.config.DatabaseDescriptor; import org.apache.cassandra.db.compaction.OperationType; import org.apache.cassandra.dht.AbstractBounds; -import org.apache.cassandra.io.sstable.Descriptor; import org.apache.cassandra.io.sstable.SSTableReader; import org.apache.cassandra.io.util.FileUtils; import org.apache.cassandra.metrics.StorageMetrics; @@ -110,7 +109,7 @@ public class DataTracker public Memtable switchMemtable() { // atomically change the current memtable - Memtable newMemtable = new Memtable(cfstore); + Memtable newMemtable = new Memtable(cfstore, view.get().memtable); Memtable toFlushMemtable; View currentView, newView; do @@ -131,7 +130,7 @@ public class DataTracker */ public void renewMemtable() { - Memtable newMemtable = new Memtable(cfstore); + Memtable newMemtable = new Memtable(cfstore, view.get().memtable); View currentView, newView; do { @@ -322,7 +321,7 @@ public class DataTracker /** (Re)initializes the tracker, purging all references. */ void init() { - view.set(new View(new Memtable(cfstore), + view.set(new View(new Memtable(cfstore, null), Collections.<Memtable>emptySet(), Collections.<SSTableReader>emptySet(), Collections.<SSTableReader>emptySet(), http://git-wip-us.apache.org/repos/asf/cassandra/blob/47bbfe35/src/java/org/apache/cassandra/db/Memtable.java ---------------------------------------------------------------------- diff --git a/src/java/org/apache/cassandra/db/Memtable.java b/src/java/org/apache/cassandra/db/Memtable.java index 1d26779..b26b7cd 100644 --- a/src/java/org/apache/cassandra/db/Memtable.java +++ b/src/java/org/apache/cassandra/db/Memtable.java @@ -46,6 +46,18 @@ public class Memtable { private static final Logger logger = LoggerFactory.getLogger(Memtable.class); + // size in memory can never be less than serialized size. + private static final double MIN_SANE_LIVE_RATIO = 1.0; + // max liveratio seen w/ 1-byte columns on a 64-bit jvm was 19. If it gets higher than 64 something is probably broken. + private static final double MAX_SANE_LIVE_RATIO = 64.0; + // reasonable initial live ratio used until we compute one. + private static final double INITIAL_LIVE_RATIO = 10.0; + + // ratio of in-memory memtable size, to serialized size + private volatile double liveRatio = INITIAL_LIVE_RATIO; + // ops count last time we computed liveRatio + private final AtomicLong liveRatioComputedAt = new AtomicLong(32); + /* * switchMemtable puts Memtable.getSortedContents on the writer executor. When the write is complete, * we turn the writer into an SSTableReader and add it to ssTables where it is available for reads. @@ -66,11 +78,6 @@ public class Memtable new NamedThreadFactory("FlushWriter"), "internal"); - // size in memory can never be less than serialized size - private static final double MIN_SANE_LIVE_RATIO = 1.0; - // max liveratio seen w/ 1-byte columns on a 64-bit jvm was 19. If it gets higher than 64 something is probably broken. - private static final double MAX_SANE_LIVE_RATIO = 64.0; - // We need to take steps to avoid retaining inactive membtables in memory, because counting is slow (can be // minutes, for a large memtable and a busy server). A strictly FIFO Memtable queue could keep memtables // alive waiting for metering after they're flushed and would otherwise be GC'd. Instead, the approach we take @@ -113,12 +120,20 @@ public class Memtable // memtable was created with the new or old comparator. public final AbstractType initialComparator; - public Memtable(ColumnFamilyStore cfs) + public Memtable(ColumnFamilyStore cfs, Memtable previous) { this.cfs = cfs; this.initialComparator = cfs.metadata.comparator; this.cfs.scheduleFlush(); + // Inherit liveRatio and liveRatioCompareAt from the previous memtable, if available, + // to minimise recalculation frequency as much as possible. + if (previous != null) + { + liveRatio = previous.liveRatio; + liveRatioComputedAt.set(previous.liveRatioComputedAt.get() / 2); + } + Callable<Set<Object>> provider = new Callable<Set<Object>>() { public Set<Object> call() throws Exception @@ -134,7 +149,7 @@ public class Memtable public long getLiveSize() { - long estimatedSize = (long) (currentSize.get() * cfs.liveRatio); + long estimatedSize = (long) (currentSize.get() * liveRatio); // liveRatio is just an estimate; we can get a lower bound directly from the allocator if (estimatedSize < allocator.getMinimumSize()) @@ -158,6 +173,23 @@ public class Memtable resolve(key, columnFamily, indexer); } + public void maybeUpdateLiveRatio() + { + // recompute liveRatio, if we have doubled the number of ops since last calculated + while (true) + { + long last = liveRatioComputedAt.get(); + long operations = currentOperations.get(); + if (operations < 2 * last) + break; + if (liveRatioComputedAt.compareAndSet(last, operations)) + { + logger.debug("computing liveRatio of {} at {} ops", this, operations); + updateLiveRatio(); + } + } + } + public void updateLiveRatio() throws RuntimeException { if (!MemoryMeter.isInitialized()) @@ -165,7 +197,7 @@ public class Memtable // hack for openjdk. we log a warning about this in the startup script too. logger.error("MemoryMeter uninitialized (jamm not specified as java agent); assuming liveRatio of {}. " + " Usually this means cassandra-env.sh disabled jamm because you are using a buggy JRE; " - + " upgrade to the Sun JRE instead", cfs.liveRatio); + + " upgrade to the Sun JRE instead", liveRatio); return; } @@ -440,14 +472,14 @@ public class Memtable } // we want to be very conservative about our estimate, since the penalty for guessing low is OOM - // death. thus, higher estimates are believed immediately; lower ones are averaged w/ the old - if (newRatio > cfs.liveRatio) - cfs.liveRatio = newRatio; + // death. thus, higher estimates are believed immediately; lower ones are averaged w/ the old + if (newRatio > memtable.liveRatio) + memtable.liveRatio = newRatio; else - cfs.liveRatio = (cfs.liveRatio + newRatio) / 2.0; + memtable.liveRatio = (memtable.liveRatio + newRatio) / 2.0; logger.info("{} liveRatio is {} (just-counted was {}). calculation took {}ms for {} cells", - cfs, cfs.liveRatio, newRatio, TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - start), objects); + cfs, memtable.liveRatio, newRatio, TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - start), objects); } finally {
