com.bigdata.journal

Interface Journal.Options

All Superinterfaces:

AbstractStatisticsCollector.Options, ConcurrencyManager.Options, HttpPlugin.Options, IServiceShutdown.Options, Options, PlatformStatsPlugIn.Options, QueueStatsPlugIn.Options, TemporaryStoreFactory.Options

All Known Subinterfaces:

StressTestGroupCommit.TestOptions

Enclosing class:

Journal

public static interface Journal.Options
extends Options, ConcurrencyManager.Options, TemporaryStoreFactory.Options, QueueStatsPlugIn.Options, PlatformStatsPlugIn.Options, HttpPlugin.Options

Options understood by the Journal.

Author:

Bryan Thompson

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_GROUP_COMMIT
static String	DEFAULT_LOCATOR_CACHE_CAPACITY
static String	DEFAULT_LOCATOR_CACHE_TIMEOUT
static String	DEFAULT_READ_POOL_SIZE
static String	GROUP_COMMIT The name of an boolean option that conditionally enables group commit semantics for the Journal based on task-oriented concurrent writers.
static String	LOCATOR_CACHE_CAPACITY The capacity of the HardReferenceQueue backing the IResourceLocator maintained by the Journal.
static String	LOCATOR_CACHE_TIMEOUT The timeout in milliseconds for stale entries in the IResourceLocator cache -or- ZERO (0) to disable the timeout (default "60000").
static String	READ_POOL_SIZE The #of threads that will be used to read on the local disk.

Fields inherited from interface com.bigdata.journal.Options

ALTERNATE_ROOT_BLOCK, BUFFER_MODE, CREATE, CREATE_TEMP_FILE, CREATE_TIME, DEFAULT_BUFFER_MODE, DEFAULT_CREATE, DEFAULT_CREATE_TEMP_FILE, DEFAULT_DELETE_ON_CLOSE, DEFAULT_DELETE_ON_EXIT, DEFAULT_DOUBLE_SYNC, DEFAULT_FILE_LOCK_ENABLED, DEFAULT_FORCE_ON_COMMIT, DEFAULT_FORCE_WRITES, DEFAULT_HALOG_COMPRESSOR, DEFAULT_HISTORICAL_INDEX_CACHE_CAPACITY, DEFAULT_HISTORICAL_INDEX_CACHE_TIMEOUT, DEFAULT_HOT_CACHE_SIZE, DEFAULT_HOT_CACHE_THRESHOLD, DEFAULT_INITIAL_EXTENT, DEFAULT_LIVE_INDEX_CACHE_CAPACITY, DEFAULT_LIVE_INDEX_CACHE_TIMEOUT, DEFAULT_MAXIMUM_EXTENT, DEFAULT_MINIMUM_EXTENSION, DEFAULT_READ_CACHE_BUFFER_COUNT, DEFAULT_READ_ONLY, DEFAULT_USE_DIRECT_BUFFERS, DEFAULT_VALIDATE_CHECKSUM, DEFAULT_WRITE_CACHE_BUFFER_COUNT, DEFAULT_WRITE_CACHE_COMPACTION_THRESHOLD, DEFAULT_WRITE_CACHE_ENABLED, DEFAULT_WRITE_CACHE_MIN_CLEAN_LIST_SIZE, DELETE_ON_CLOSE, DELETE_ON_EXIT, DOUBLE_SYNC, FILE, FILE_LOCK_ENABLED, FORCE_ON_COMMIT, FORCE_WRITES, HALOG_COMPRESSOR, HISTORICAL_INDEX_CACHE_CAPACITY, HISTORICAL_INDEX_CACHE_TIMEOUT, HOT_CACHE_SIZE, HOT_CACHE_THRESHOLD, IGNORE_BAD_ROOT_BLOCK, INITIAL_EXTENT, JNL, LIVE_INDEX_CACHE_CAPACITY, LIVE_INDEX_CACHE_TIMEOUT, MAXIMUM_EXTENT, MEM_MAX_EXTENT, MINIMUM_EXTENSION, minimumInitialExtent, minimumMinimumExtension, OFFSET_BITS, OTHER_MAX_EXTENT, READ_CACHE_BUFFER_COUNT, READ_ONLY, RW_MAX_EXTENT, SEG, TMP_DIR, UPDATE_ICU_VERSION, USE_DIRECT_BUFFERS, VALIDATE_CHECKSUM, WRITE_CACHE_BUFFER_COUNT, WRITE_CACHE_COMPACTION_THRESHOLD, WRITE_CACHE_ENABLED, WRITE_CACHE_MIN_CLEAN_LIST_SIZE

Fields inherited from interface com.bigdata.journal.ConcurrencyManager.Options

DEFAULT_READ_SERVICE_CORE_POOL_SIZE, DEFAULT_TX_SERVICE_CORE_POOL_SIZE, DEFAULT_WRITE_SERVICE_CORE_POOL_SIZE, DEFAULT_WRITE_SERVICE_GROUP_COMMIT_TIMEOUT, DEFAULT_WRITE_SERVICE_KEEP_ALIVE_TIME, DEFAULT_WRITE_SERVICE_MAXIMUM_POOL_SIZE, DEFAULT_WRITE_SERVICE_OVERFLOW_LOCK_REQUEST_TIMEOUT, DEFAULT_WRITE_SERVICE_PRESTART_ALL_CORE_THREADS, DEFAULT_WRITE_SERVICE_QUEUE_CAPACITY, READ_SERVICE_CORE_POOL_SIZE, TX_SERVICE_CORE_POOL_SIZE, WRITE_SERVICE_CORE_POOL_SIZE, WRITE_SERVICE_GROUP_COMMIT_TIMEOUT, WRITE_SERVICE_KEEP_ALIVE_TIME, WRITE_SERVICE_MAXIMUM_POOL_SIZE, WRITE_SERVICE_OVERFLOW_LOCK_REQUEST_TIMEOUT, WRITE_SERVICE_PRESTART_ALL_CORE_THREADS, WRITE_SERVICE_QUEUE_CAPACITY

Fields inherited from interface com.bigdata.service.IServiceShutdown.Options

DEFAULT_SHUTDOWN_TIMEOUT, SHUTDOWN_TIMEOUT

Fields inherited from interface com.bigdata.journal.TemporaryStoreFactory.Options

DEFAULT_MAX_EXTENT, DEFAULT_OFFSET_BITS, JAVA_TMP_DIR_PROPERTY, MAX_EXTENT, OFFSET_BITS, TMP_DIR

Fields inherited from interface com.bigdata.journal.QueueStatsPlugIn.Options

COLLECT_QUEUE_STATISTICS, DEFAULT_COLLECT_QUEUE_STATISTICS

Fields inherited from interface com.bigdata.journal.PlatformStatsPlugIn.Options

COLLECT_PLATFORM_STATISTICS, DEFAULT_COLLECT_PLATFORM_STATISTICS

Fields inherited from interface com.bigdata.counters.AbstractStatisticsCollector.Options

DEFAULT_PERFORMANCE_COUNTERS_SAMPLE_INTERVAL, PERFORMANCE_COUNTERS_SAMPLE_INTERVAL, PROCESS_NAME

Fields inherited from interface com.bigdata.journal.HttpPlugin.Options

DEFAULT_HTTPD_PORT, HTTPD_PORT

Field Detail

GROUP_COMMIT

static final String GROUP_COMMIT

The name of an boolean option that conditionally enables group commit semantics for the Journal based on task-oriented concurrent writers. This option indicates a contract that the application agrees to respect. When false the application controls when the database goes through a commit point by invoking AbstractJournal.commit(). When true ALL mutation operations MUST be submitted to the IConcurrencyManager of the journal. Note that the journal always has supported group commit - this is how it is used in scale-out. However, embedded applications have historically made the decision about when the database should commit. When you specify this option, you are asserting that your code will always submit tasks for evaluation using the IConcurrencyManager.

There are several benefits of group commit.

First, you can have multiple tenants in the same database instance and the updates for one tenant will no longer block the updates for the other tenants. Thus, one tenant can be safely running a long running update and other tenants can still enjoy low latency updates.

Second, group commit automatically combines a sequence of updates on one (or more) tenant(s) into a single commit point on the disk. This provides higher potential throughput. It also means that it is no longer as important for applications to batch their updates since group commit will automatically perform some batching.

Third, writes on independent indices may be independent (this behavior has been around for a long time).

There are a few "gotchas" with the group commit support. This is because commits are decided by IApiTask or AbstractTask completion and tasks are scheduled by the concurrency manager, lock manager, and write executor service.

• Mutation tasks that do not complete normally MUST throw an exception!
• Applications MUST NOT call Journal.commit(). Instead, they submit an IApiTask using AbstractApiTask.submit(). The database will meld the write set of the task into a group commit sometime after the task completes successfully.

See Also:

(NSS GROUP COMMIT).

DEFAULT_GROUP_COMMIT

static final String DEFAULT_GROUP_COMMIT

See Also:

Constant Field Values

LOCATOR_CACHE_CAPACITY

static final String LOCATOR_CACHE_CAPACITY

The capacity of the HardReferenceQueue backing the IResourceLocator maintained by the Journal. The capacity of this cache indirectly controls how many ILocatableResources the Journal will hold open.

The effect of this parameter is indirect owning to the semantics of weak references and the control of the JVM over when they are cleared. Once an ILocatableResource becomes weakly reachable, the JVM will eventually GC the object. Since objects which are strongly reachable are never cleared, this provides our guarantee that resources are never closed if they are in use.

See Also:

DEFAULT_LOCATOR_CACHE_CAPACITY

DEFAULT_LOCATOR_CACHE_CAPACITY

static final String DEFAULT_LOCATOR_CACHE_CAPACITY

See Also:

Constant Field Values

LOCATOR_CACHE_TIMEOUT

static final String LOCATOR_CACHE_TIMEOUT

The timeout in milliseconds for stale entries in the IResourceLocator cache -or- ZERO (0) to disable the timeout (default "60000"). When this timeout expires, the reference for the entry in the backing HardReferenceQueue will be cleared. Note that the entry will remain in the IResourceLocator cache regardless as long as it is strongly reachable.

DEFAULT_LOCATOR_CACHE_TIMEOUT

static final String DEFAULT_LOCATOR_CACHE_TIMEOUT

See Also:

Constant Field Values

READ_POOL_SIZE

static final String READ_POOL_SIZE

The #of threads that will be used to read on the local disk.

See Also:

Journal.getReadExecutor()

DEFAULT_READ_POOL_SIZE

static final String DEFAULT_READ_POOL_SIZE

See Also:

Constant Field Values