/**
* Sets the maximum segment size in bytes, returning the builder for method chaining.
*
* <p>The maximum segment size dictates when logs should roll over to new segments. As entries
* are written to a segment of the log, once the size of the segment surpasses the configured
* maximum segment size, the log will create a new segment and append new entries to that
* segment.
*
* <p>By default, the maximum segment size is {@code 1024 * 1024 * 32}.
*
* @param maxSegmentSize The maximum segment size in bytes.
* @return The storage builder.
* @throws IllegalArgumentException If the {@code maxSegmentSize} is not positive
*/
public Builder withMaxSegmentSize(int maxSegmentSize) {
Assert.arg(
maxSegmentSize > SegmentDescriptor.BYTES,
"maxSegmentSize must be greater than " + SegmentDescriptor.BYTES);
storage.maxSegmentSize = maxSegmentSize;
return this;
}
/**
* Returns a new Atomix replica builder from the given properties.
*
* @param properties The properties from which to load the replica builder.
* @return The replica builder.
*/
public static Builder builder(Properties properties) {
ReplicaProperties replicaProperties = new ReplicaProperties(properties);
Collection<Address> replicas = replicaProperties.replicas();
return builder(replicaProperties.clientAddress(), replicaProperties.serverAddress(), replicas)
.withTransport(replicaProperties.transport())
.withStorage(
Storage.builder()
.withStorageLevel(replicaProperties.storageLevel())
.withDirectory(replicaProperties.storageDirectory())
.withMaxSegmentSize(replicaProperties.maxSegmentSize())
.withMaxEntriesPerSegment(replicaProperties.maxEntriesPerSegment())
.withMaxSnapshotSize(replicaProperties.maxSnapshotSize())
.withRetainStaleSnapshots(replicaProperties.retainStaleSnapshots())
.withCompactionThreads(replicaProperties.compactionThreads())
.withMinorCompactionInterval(replicaProperties.minorCompactionInterval())
.withMajorCompactionInterval(replicaProperties.majorCompactionInterval())
.withCompactionThreshold(replicaProperties.compactionThreshold())
.build())
.withSerializer(replicaProperties.serializer())
.withQuorumHint(
replicaProperties.quorumHint() != -1 ? replicaProperties.quorumHint() : replicas.size())
.withBackupCount(replicaProperties.backupCount())
.withElectionTimeout(replicaProperties.electionTimeout())
.withHeartbeatInterval(replicaProperties.heartbeatInterval())
.withSessionTimeout(replicaProperties.sessionTimeout());
}
/**
* Sets the maximum number of allows entries per segment, returning the builder for method
* chaining.
*
* <p>The maximum entry count dictates when logs should roll over to new segments. As entries
* are written to a segment of the log, if the entry count in that segment meets the configured
* maximum entry count, the log will create a new segment and append new entries to that
* segment.
*
* <p>By default, the maximum entries per segment is {@code 1024 * 1024}.
*
* @param maxEntriesPerSegment The maximum number of entries allowed per segment.
* @return The storage builder.
* @throws IllegalArgumentException If the {@code maxEntriesPerSegment} not greater than the
* default max entries per segment
*/
public Builder withMaxEntriesPerSegment(int maxEntriesPerSegment) {
Assert.arg(maxEntriesPerSegment > 0, "max entries per segment must be positive");
Assert.argNot(
maxEntriesPerSegment > DEFAULT_MAX_ENTRIES_PER_SEGMENT,
"max entries per segment cannot be greater than " + DEFAULT_MAX_ENTRIES_PER_SEGMENT);
storage.maxEntriesPerSegment = maxEntriesPerSegment;
return this;
}
/** Sets up a server state. */
@BeforeMethod
void beforeMethod() throws Throwable {
serializer = new Serializer();
serializer.resolve(new ServiceLoaderTypeResolver());
storage = new Storage(StorageLevel.MEMORY);
storage.serializer().resolve(new ServiceLoaderTypeResolver());
log = storage.open("test");
stateMachine = new TestStateMachine();
members = createMembers(3);
transport = new LocalTransport(new LocalServerRegistry());
serverCtx = new SingleThreadContext("test-server", serializer);
serverState =
new ServerState(
members.get(0),
members,
log,
stateMachine,
new ConnectionManager(transport.client()),
serverCtx);
}
/**
* Sets the percentage of entries in the segment that must be cleaned before a segment can be
* compacted, returning the builder for method chaining.
*
* <p>The compaction threshold is used during {@link
* io.atomix.copycat.server.storage.compaction.Compaction#MINOR minor compaction} to determine
* the set of segments to compact. By default, the compaction threshold is {@code 0.5}.
* Increasing the compaction threshold will increase the number of {@link
* io.atomix.copycat.server.storage.entry.Entry entries} that must be cleaned from the segment
* before compaction and thus decrease the likelihood that a segment will be compacted.
* Conversely, decreasing the compaction threshold will increase the frequency of compaction at
* the cost of unnecessary I/O.
*
* @see io.atomix.copycat.server.storage.compaction.MinorCompactionManager
* @param threshold The segment compact threshold.
* @return The storage builder.
*/
public Builder withCompactionThreshold(double threshold) {
storage.compactionThreshold =
Assert.argNot(threshold, threshold <= 0, "threshold must be positive");
return this;
}
/**
* Sets the major compaction interval, returning the builder for method chaining.
*
* <p>The major compaction interval dictates the interval at which the {@link
* io.atomix.copycat.server.storage.compaction.MajorCompactionManager} should evaluate {@link
* Segment}s in the log for major compaction. Because of the performance costs of major
* compaction, it is recommended that the major compaction interval be at least an order of
* magnitude greater than the minor compaction interval.
*
* @see io.atomix.copycat.server.storage.compaction.MajorCompactionManager
* @see io.atomix.copycat.server.storage.compaction.MajorCompactionTask
* @param interval The major compaction interval.
* @return The storage builder.
*/
public Builder withMajorCompactionInterval(Duration interval) {
storage.majorCompactionInterval = Assert.notNull(interval, "interval");
return this;
}
/**
* Sets the number of log compaction threads, returning the builder for method chaining.
*
* <p>The compaction thread count dictates the parallelism with which the log {@link
* io.atomix.copycat.server.storage.compaction.Compactor} can rewrite segments in the log. By
* default, the log uses {@code Runtime.getRuntime().availableProcessors() / 2} compaction
* threads.
*
* @param compactionThreads The number of log compaction threads.
* @return The storage builder.
* @throws IllegalArgumentException if {@code compactionThreads} is not positive
*/
public Builder withCompactionThreads(int compactionThreads) {
storage.compactionThreads =
Assert.arg(
compactionThreads, compactionThreads > 0, "compactionThreads must be positive");
return this;
}
/**
* Sets whether to retain stale snapshots on disk, returning the builder for method chaining.
*
* <p>As the system state progresses, periodic snapshots of the state machine's state are taken.
* Once a new snapshot of the state machine is taken, all preceding snapshots no longer
* contribute to the state of the system and can therefore be removed from disk. By default,
* snapshots will not be retained once a new snapshot is stored on disk. Enabling snapshot
* retention will ensure that all snapshots will be saved, e.g. for backup purposes.
*
* @param retainStaleSnapshots Whether to retain stale snapshots on disk.
* @return The storage builder.
*/
public Builder withRetainStaleSnapshots(boolean retainStaleSnapshots) {
storage.retainStaleSnapshots = retainStaleSnapshots;
return this;
}
/**
* Sets the maximum size of snapshot files on disk, returning the builder for method chaining.
*
* <p>The maximum snapshot size dictates the size in bytes of a single snapshot file on disk.
* Reducing the maximum snapshot file size can help ensure that the system is not bogged down
* with storing and replicating snapshots. By default, snapshots are practically unlimited with
* a 2GB limit, but in practice they should be fairly small.
*
* @param maxSnapshotSize The maximum snapshot size in bytes.
* @return The storage builder.
* @throws IllegalArgumentException if the {@code maxSnapshotSize} is not positive or is less
* than {@code 64}
*/
public Builder withMaxSnapshotSize(int maxSnapshotSize) {
storage.maxSnapshotSize =
Assert.arg(maxSnapshotSize, maxSnapshotSize >= 64, "max snapshot size must be positive");
return this;
}
/**
* Sets the log directory, returning the builder for method chaining.
*
* <p>The log will write segment files into the provided directory. If multiple {@link Storage}
* objects are located on the same machine, they write logs to different directories.
*
* @param directory The log directory.
* @return The storage builder.
* @throws NullPointerException If the {@code directory} is {@code null}
*/
public Builder withDirectory(File directory) {
storage.directory = Assert.notNull(directory, "directory");
return this;
}
/**
* Sets the log storage level, returning the builder for method chaining.
*
* <p>The storage level indicates how individual {@link
* io.atomix.copycat.server.storage.entry.Entry entries} should be persisted in the log.
*
* @param storageLevel The log storage level.
* @return The storage builder.
*/
public Builder withStorageLevel(StorageLevel storageLevel) {
storage.storageLevel = Assert.notNull(storageLevel, "storageLevel");
return this;
}
protected Storage.Builder tempStorageBuilder() {
return Storage.builder().withDirectory(new File(String.format("target/test-logs/%s", logId)));
}