FileStoreMBean

Overview

Defines an instance of the persistent store on the specified target that will keep its persistent objects in files on the filesystem. It may be used by JMS and by other subsystems.

Related MBeans

This section describes attributes that provide access to other MBeans.

Targets

The server instances, clusters, or migratable targets defined in the current domain that are candidates for hosting a file store, JDBC store, or replicated store. If scoped to a Resource Group or Resource Group Template, the target is inherited from the Virtual Target.

When selecting a cluster, the store must be targeted to the same cluster as the JMS server. When selecting a migratable target, the store must be targeted it to the same migratable target as the migratable JMS server or SAF agent. As a best practice, a path service should use its own custom store and share the same target as the store.

Attributes

This section describes the following attributes:

BlockSize

The smallest addressable block, in bytes, of a file. When a native wlfileio driver is available and the block size has not been configured by the user, the store selects the minimum OS specific value for unbuffered (direct) I/O, if it is within the range [512, 8192].

A file store's block size does not change once the file store creates its files. Changes to block size only take effect for new file stores or after the current files have been deleted. See "Tuning the Persistent Store" in Tuning Performance of Oracle WebLogic Server.

CacheDirectory

The location of the cache directory for Direct-Write-With-Cache, ignored for other policies.

When Direct-Write-With-Cache is specified as the SynchronousWritePolicy, cache files are created in addition to primary files (see Directory for the location of primary files). If a cache directory location is specified, the cache file path is CacheDirectory/WLStoreCache/StoreNameFileNum.DAT.cache. When specified, Oracle recommends using absolute paths, but if the directory location is a relative path, then CacheDirectory is created relative to the WebLogic Server instance's home directory. If "" or Null is specified, the Cache Directory is located in the current operating system temp directory as determined by the java.io.tmpdir Java System property (JDK's default: /tmp on UNIX, %TEMP% on Windows) and is TempDirectory/WLStoreCache/DomainName/unique-id/ StoreNameFileNum.DAT.cache. The value of java.io.tmpdir varies between operating systems and configurations, and can be overridden by passing -Djava.io.tmpdir=My_path on the JVM command line.

Considerations:

• Security: Some users may want to set specific directory permissions to limit access to the cache directory, especially if there are custom configured user access limitations on the primary directory. For a complete guide to WebLogic security, see "Securing a Production Environment for Oracle WebLogic Server."

• Additional Disk Space Usage: Cache files consume the same amount of disk space as the primary store files that they mirror. See Directory for the location of primary store files.

• Performance: For the best performance, a cache directory should be located in local storage instead of NAS/SAN (remote) storage, preferably in the operating system's temp directory. Relative paths should be avoided, as relative paths are located based on the domain installation, which is typically on remote storage. It is safe to delete a cache directory while the store is not running, but this may slow down the next store boot.

• Preventing Corruption and File Locking: Two same named stores must not be configured to share the same primary or cache directory. There are store file locking checks that are designed to detect such conflicts and prevent corruption by failing the store boot, but it is not recommended to depend on the file locking feature for correctness. See Enable File Locking.

• Boot Recovery: Cache files are reused to speed up the File Store boot and recovery process, but only if the store's host WebLogic Server instance has been shut down cleanly prior to the current boot. For example, cache files are not re-used and are instead fully recreated: after a kill -9, after an OS or JVM crash, or after an off-line change to the primary files, such as a store admin compaction. When cache files are recreated, a Warning log message 280102 is generated.

• Fail-Over/Migration Recovery: A file store safely recovers its data without its cache directory. Therefore, a cache directory does not need to be copied or otherwise made accessible after a fail-over or migration, and similarly does not need to be placed in NAS/SAN storage. A Warning log message 280102, which is generated to indicate the need to recreate the cache on the new host system, can be ignored.

• Cache File Cleanup: To prevent unused cache files from consuming disk space, test and developer environments should periodically delete cache files.

CachingDisabled

Private property that disables caching in proxies.

DeploymentOrder

A priority that the server uses to determine when it deploys an item. The priority is relative to other deployable items of the same type.

For example, the server prioritizes and deploys all EJBs before it prioritizes and deploys startup classes.

Items with the lowest Deployment Order value are deployed first. There is no guarantee on the order of deployments with equal Deployment Order values. There is no guarantee of ordering across clusters.

Directory

The path name to the file system directory where the file store maintains its data files.

• When targeting a file store to a migratable target, the store directory must be accessible from all candidate server members in the migratable target.

• For highest availability, use either a SAN (Storage Area Network) or other reliable shared storage.

• Use of NFS mounts is discouraged, but supported. Most NFS mounts are not transactionally safe by default, and, to ensure transactional correctness, need to be configured using your NFS vendor documentation in order to honor synchronous write requests.

• For SynchronousWritePolicy of Direct-Write-With-Cache, see Cache Directory.

• Additional O/S tuning may be required if the directory is hosted by Microsoft Windows, see Synchronous Write Policy for details.

DistributionPolicy

Specifies how the instances of a configured JMS artifact are named and distributed when cluster-targeted. A JMS artifact is cluster-targeted when its target is directly set to a cluster, or when it is scoped to a resource group and the resource group is in turn targeted to a cluster. When this setting is configured on a store, it applies to all JMS artifacts that reference the store. Valid options:

• Distributed

  Creates an instance on each server JVM in a cluster. Required for all SAF agents and for cluster-targeted or resource-group-scoped JMS servers that host distributed destinations.

• Singleton

  Creates a single instance on a single server JVM within a cluster. Required for cluster-targeted or resource-group-scoped JMS servers that host standalone (non-distributed) destinations and for cluster-targeted or resource-group-scoped path services. The Migration Policy must be On-Failure or Always when using this option with a JMS server, On-Failure when using this option with a messaging bridge, and Always when using this option with a path service.

Instance Naming Note:

• The DistributionPolicy determines the instance name suffix for cluster-targeted JMS artifacts. The suffix for a cluster-targeted Singleton is -01 and for a cluster-targeted Distributed is @ClusterMemberName.

Messaging Bridge Notes:

• When an instance per server is desired for a cluster-targeted messaging bridge, Oracle recommends setting the bridge Distributed Policy and Migration Policy to Distributed/Off, respectively; these are the defaults.

• When a single instance per cluster is desired for a cluster-targeted bridge, Oracle recommends setting the bridge Distributed Policy and Migration Policy to Singleton/On-Failure, respectively.

• If you cannot cluster-target a bridge and still need singleton behavior in a configured cluster, you can target the bridge to a migratable target and configure the Migration Policy on the migratable target to Exactly-Once.

For more information, see:

• getMigrationPolicy
• setDistributionPolicy

DynamicallyCreated

Return whether the MBean was created dynamically or is persisted to config.xml

FailbackDelaySeconds

Specifies the amount of time, in seconds, to delay before failing a cluster-targeted JMS artifact instance back to its preferred server after the preferred server failed and was restarted.

This delay allows time for the system to stabilize and dependent services to be restarted, preventing a system failure during a reboot.

• A value > 0 specifies the time, in seconds, to delay before failing a JMS artifact back to its user preferred server.

• A value of 0 indicates that the instance would never failback.

• A value of -1 indicates that there is no delay and the instance would failback immediately.

This setting only applies when the JMS artifact is cluster-targeted and the Migration Policy is set to On-Failure or Always.

FailOverLimit

Specify a limit for the number of cluster-targeted JMS artifact instances that can fail over to a particular JVM.

This can be used to prevent too many instances from starting on a server, avoiding a system failure when starting too few servers of a formerly large cluster.

A typical limit value should allow all instances to run in the smallest desired cluster size, which means (smallest-cluster-size * (limit + 1)) should equal or exceed the total number of instances.

• A value of -1 means there is no fail over limit (unlimited).

• A value of 0 prevents any fail overs of cluster-targeted JMS artifact instances, so no more than 1 instance will run per server (this is an instance that has not failed over).

• A value of 1 allows one fail-over instance on each server, so no more than two instances will run per server (one failed over instance plus an instance that has not failed over).

This setting only applies when the JMS artifact is cluster-targeted and the Migration Policy is set to On-Failure or Always.

FileLockingEnabled

Determines whether OS file locking is used.

When file locking protection is enabled, a store boot fails if another store instance already has opened the store files. Do not disable this setting unless you have procedures in place to prevent multiple store instances from opening the same file. File locking is not required but helps prevent corruption in the event that two same-named file store instances attempt to operate in the same directories. This setting applies to both primary and cache files.

For more information, see:

• getDirectory
• getCacheDirectory

Id

Return the unique id of this MBean instance

InitialBootDelaySeconds

Specifies the amount of time, in seconds, to delay before starting a cluster-targeted JMS instance on a newly booted WebLogic Server instance. When this setting is configured on a store, it applies to all JMS artifacts that reference the store.

This allows time for the system to stabilize and dependent services to be restarted, preventing a system failure during a reboot.

• A value > 0 is the time, in seconds, to delay before before loading resources after a failure and restart.

• A value of 0 specifies no delay.

This setting only applies when the JMS artifact is cluster-targeted and the Migration Policy is set to On-Failure or Always.

For more information, see:

• PartialClusterStabilityDelaySeconds

InitialSize

The initial file size, in bytes.

• Set InitialSize to pre-allocate file space during a file store boot. If InitialSize exceeds MaxFileSize, a store creates multiple files (number of files = InitialSize/MaxFileSize rounded up).

• A file store automatically reuses the space from deleted records and automatically expands a file if there is not enough space for a new write request.

• Use InitialSize to limit or prevent file expansions during runtime, as file expansion introduces temporary latencies that may be noticeable under rare circumstances.

• Changes to initial size only take effect for new file stores, or after any current files have been deleted prior to restart.

• See Maximum File Size.

IoBufferSize

The I/O buffer size, in bytes, automatically rounded down to the nearest power of 2.

• For the Direct-Write-With-Cache policy when a native wlfileio driver is available, IOBufferSize describes the maximum portion of a cache view that is passed to a system call. This portion does not consume off-heap (native) or Java heap memory.

• For the Direct-Write and Cache-Flush policies, IOBufferSize is the size of a per store buffer which consumes off-heap (native) memory, where one buffer is allocated during run-time, but multiple buffers may be temporarily created during boot recovery.

• When a native wlfileio driver is not available, the setting applies to off-heap (native) memory for all policies (including Disabled).

• For the best runtime performance, Oracle recommends setting IOBufferSize so that it is larger than the largest write (multiple concurrent store requests may be combined into a single write).

• For the best boot recovery time performance of large stores, Oracle recommends setting IOBufferSize to at least 2 megabytes.

See AllocatedIOBufferBytes to find out the actual allocated off-heap (native) memory amount. It is a multiple of IOBufferSize for the Direct-Write and Cache-Flush policies, or zero.

LogicalName

The name used by subsystems to refer to different stores on different servers using the same name.

For example, an EJB that uses the timer service may refer to its store using the logical name, and this name may be valid on multiple servers in the same cluster, even if each server has a store with a different physical name.

Multiple stores in the same domain or the same cluster may share the same logical name. However, a given logical name may not be assigned to more than one store on the same server.

MaxFileSize

The maximum file size, in bytes, of an individual data file.

• The MaxFileSize value affects the number of files needed to accommodate a store of a particular size (number of files = store size/MaxFileSize rounded up).

• A file store automatically reuses space freed by deleted records and automatically expands individual files up to MaxFileSize if there is not enough space for a new record. If there is no space left in exiting files for a new record, a store creates an additional file.

• A small number of larger files is normally preferred over a large number of smaller files as each file allocates Window Buffer and file handles.

• If MaxFileSize is larger than 2^24 * BlockSize, then MaxFileSize is ignored, and the value becomes 2^24 * BlockSize. The default BlockSize is 512, and 2^24 * 512 is 8 GB.

• The minimum size for MaxFileSize is 10 MB when multiple data files are used by the store. If InitialSize is less than MaxFileSize then a single file will be created of InitialSize bytes. If InitialSize is larger than MaxFileSize then (InitialSize / MaxFileSize) files will be created of MaxFileSize bytes and an additional file if necessary to contain any remainder.

• See Initial Size.

MaxWindowBufferSize

The maximum amount of data, in bytes and rounded down to the nearest power of 2, mapped into the JVM's address space per primary store file. Applies to synchronous write policies Direct-Write-With-Cache and Disabled but only when the native wlfileio library is loaded.

A window buffer does not consume Java heap memory, but does consume off-heap (native) memory. If the store is unable to allocate the requested buffer size, it allocates smaller and smaller buffers until it reaches MinWindowBufferSize, and then fails if cannot honor MinWindowBufferSize.

Oracle recommends setting the max window buffer size to more than double the size of the largest write (multiple concurrently updated records may be combined into a single write), and greater than or equal to the file size, unless there are other constraints. 32-bit JVMs may impose a total limit of between 2 and 4GB for combined Java heap plus off-heap (native) memory usage.

• See store attribute AllocatedWindowBufferBytes to find out the actual allocated Window Buffer Size.

• See Maximum File Size and Minimum Window Buffer Size.

MBeanInfo

Returns the MBean info for this MBean.

Deprecated.

MigrationPolicy

Controls migration and restart behavior of cluster-targeted JMS service artifact instances. When this setting is configured on a cluster-targeted store, it applies to all JMS artifacts that reference the store. See the migratable target settings for enabling migration and restart on migratable-targeted JMS artifacts.

• Off

  Disables migration support for cluster-targeted JMS service objects, and changes the default for Restart In Place to false. If you want a restart to be enabled when the Migration Policy is Off, then Restart In Place must be explicitly configured to true. This policy cannot be combined with the Singleton Migration Policy.

• On-Failure

  Enables automatic migration and restart of instances on the failure of a subsystem Service or WebLogic Server instance, including automatic fail-back and load balancing of instances.

• Always

  Provides the same behavior as On-Failure and automatically migrates instances even in the event of a graceful shutdown or a partial cluster start.

Cluster leasing must be configured for On-Failure and Always.

Messaging Bridge Notes:

• When an instance per server is desired for a cluster-targeted messaging bridge, Oracle recommends setting the bridge Distributed Policy and Migration Policy to Distributed/Off, respectively; these are the defaults.

• When a single instance per cluster is desired for a cluster-targeted bridge, Oracle recommends setting the bridge Distributed Policy and Migration Policy to Singleton/On-Failure, respectively.

• A Migration Policy of Always is not recommended for bridges.

• If you cannot cluster-target a bridge and still need singleton behavior in a configured cluster, you can target the bridge to a migratable target and configure the Migration Policy on the migratable target to Exactly-Once.

For more information, see:

• setMigrationPolicy

MinWindowBufferSize

The minimum amount of data, in bytes and rounded down to the nearest power of 2, mapped into the JVM's address space per primary store file. Applies to synchronous write policies Direct-Write-With-Cache and Disabled, but only when a native wlfileio library is loaded. See Maximum Window Buffer Size.

Name

The user-specified name of this MBean instance.

This name is included as one of the key properties in the MBean's javax.management.ObjectName:

Name=user-specified-name

Notes

Optional information that you can include to describe this configuration.

WebLogic Server saves this note in the domain's configuration file (config.xml) as XML PCDATA. All left angle brackets (<) are converted to the XML entity <. Carriage returns/line feeds are preserved.

Note: If you create or edit a note from the Administration Console, the Administration Console does not preserve carriage returns/line feeds.

NumberOfRestartAttempts

Specifies the maximum number of restart attempts.

• A value > 0 specifies the maximum number of restart attempts.

• A value of 0specifies the same behavior as setting RestartInPlace tofalse.

• A value of -1 means infinite retry restart until it either starts or the server instance shuts down.

ObjectName

Returns the ObjectName under which this MBean is registered in the MBean server.

Deprecated.

Parent

Return the immediate parent for this MBean

PartialClusterStabilityDelaySeconds

Specifies the amount of time, in seconds, to delay before a partially started cluster starts all cluster-targeted JMS artifact instances that are configured with a Migration Policy of Always or On-Failure.

Before this timeout expires or all servers are running, a cluster starts a subset of such instances based on the total number of servers running and the configured cluster size. Once the timeout expires or all servers have started, the system considers the cluster stable and starts any remaining services.

This delay ensures that services are balanced across a cluster even if the servers are started sequentially. It is ignored after a cluster is fully started (stable) or when individual servers are started.

• A value > 0 specifies the time, in seconds, to delay before a partially started cluster starts dynamically configured services.

• A value of 0 specifies no delay.

For more information, see:

• getInitialBootDelaySeconds

RebalanceEnabled

If set to true, then rebalance running cluster-targeted JMS instances when the system is idle and instances are unevenly distributed.

The system is considered idle when the Partial Cluster Stability Delay and Initial Boot Delay have passed, and no instances have moved plus no server status has changed within the last two system check periods (typically 10 seconds between each check). Two is the default, you can tune this higher using Rebalance Delay Periods on the Cluster bean.

The system is considered unbalanced if any running server has a JMS instance count that is more than one higher than the instance count on any other running server.

The rebalance heuristic forces all running instances that are not on their preferred server to move to their preferred server if the preferred server is running. It then finds the alphanumerically highest failed-over instance on the running server with the most instances, moves this instance to the alphanumerically least most running server with the fewest failed-over instances, and repeats this pattern until there are no running servers with an instance count that is more than one higher than the instance count on any other running server.

Note: This setting only applies when the JMS artifact is cluster-targeted, its Distribution Policy is set to Distributed, and its Migration Policy is set to On-Failure or Always.

For more information, see:

• getPartialClusterStabilityDelaySeconds
• getInitialBootDelaySeconds
• ClusterMBean#getRebalanceDelayPeriods

Registered

Returns false if the MBean represented by this object has been unregistered.

Deprecated.

RestartInPlace

Enables a periodic automatic in-place restart of failed cluster-targeted or standalone-server-targeted JMS artifact instance(s) running on healthy WebLogic Server instances. See the migratable target settings for in-place restarts of migratable-targeted JMS artifacts. When the Restart In Place setting is configured on a store, it applies to all JMS artifacts that reference the store.

• If the Migration Policy of the JMS artifact is set to Off, Restart In Place is disabled by default.

• If the Migration Policy of the JMS artifact is set to On-Failure or Always, Restart In Place is enabled by default.

• This attribute is not used by WebLogic messaging bridges which automatically restart internal connections as needed.

• For a JMS artifact that is cluster-targeted and the Migration Policy is set to On-Failure or Always, if restart fails after the configured maximum retry attempts, it will migrate to a different server within the cluster.

For more information, see:

• setRestartInPlace

SecondsBetweenRestarts

Specifies the amount of time, in seconds, to wait in between attempts to restart a failed service instance.

SynchronousWritePolicy

The disk write policy that determines how the file store writes data to disk.

This policy also affects the JMS file store's performance, scalability, and reliability. Oracle recommends Direct-Write-With-Cache which tends to have the highest performance. The default value is Direct-Write. The valid policy options are:

• Direct-Write

  Direct I/O is supported on all platforms. When available, file stores in direct I/O mode automatically load the native I/O wlfileio driver. This option tends to out-perform Cache-Flush and tend to be slower than Direct-Write-With-Cache. This mode does not require a native store wlfileio driver, but performs faster when they are available.

• Direct-Write-With-Cache

  Store records are written synchronously to primary files in the directory specified by the Directory attribute and asynchronously to a corresponding cache file in the Cache Directory. The Cache Directory provides information about disk space, locking, security, and performance implications. This mode requires a native store wlfileiocode driver. If the native driver cannot be loaded, then the write mode automatically switches to Direct-Write. See Cache Directory.

• Cache-Flush

  Transactions cannot complete until all of their writes have been flushed down to disk. This policy is reliable and scales well as the number of simultaneous users increases.Transactionally safe but tends to be a lower performer than direct-write policies.

• Disabled

  Transactions are complete as soon as their writes are cached in memory, instead of waiting for the writes to successfully reach the disk. This is the fastest policy because write requests do not block waiting to be synchronized to disk, but, unlike other policies, is not transactionally safe in the event of operating system or hardware failures. Such failures can lead to duplicate or lost data/messages. This option does not require native store wlfileio drivers, but may run faster when they are available. Some non-WebLogic JMS vendors default to a policy that is equivalent to Disabled.

Notes:

• When available, file stores load WebLogic wlfileio native drivers, which can improve performance. These drivers are included with Windows, Solaris, Linux, and AIX WebLogic installations.

• Certain older versions of Microsoft Windows may incorrectly report storage device synchronous write completion if the Windows default Write Cache Enabled setting is used. This violates the transactional semantics of transactional products (not specific to Oracle), including file stores configured with a Direct-Write (default) or Direct-Write-With-Cache policy, as a system crash or power failure can lead to a loss or a duplication of records/messages. One of the visible symptoms is that this problem may manifest itself in high persistent message/transaction throughput exceeding the physical capabilities of your storage device. You can address the problem by applying a Microsoft supplied patch, disabling the Windows Write Cache Enabled setting, or by using a power-protected storage device. See http://support.microsoft.com/kb/281672 and http://support.microsoft.com/kb/332023.

• NFS storage note: On some operating systems, native driver memory-mapping is incompatible with NFS when files are locked. Stores with synchronous write policies Direct-Write-With-Cache or Disabled, and WebLogic JMS paging stores enhance performance by using the native wlfileio driver to perform memory-map operating system calls. When a store detects an incompatibility between NFS, file locking, and memory mapping, it automatically downgrades to conventional read/write system calls instead of memory mapping. For best performance, Oracle recommends investigating alternative NFS client drivers, configuring a non-NFS storage location, or in controlled environments and at your own risk, disabling the file locks (See Enable File Locking). For more information, see "Tuning the WebLogic Persistent Store" in Tuning Performance of Oracle WebLogic Server.

Tags

Return all tags on this Configuration MBean

Type

Returns the type of the MBean.

XAResourceName

Overrides the name of the XAResource that this store registers with JTA.

You should not normally set this attribute. Its purpose is to allow the name of the XAResource to be overridden when a store has been upgraded from an older release and the store contained prepared transactions. The generated name should be used in all other cases.

Operations

This section describes the following operations:

addTag

Add a tag to this Configuration MBean. Adds a tag to the current set of tags on the Configuration MBean. Tags may contain white spaces.

addTarget

Targets a server instance to a store.

freezeCurrentValue

If the specified attribute has not been set explicitly, and if the attribute has a default value, this operation forces the MBean to persist the default value.

Unless you use this operation, the default value is not saved and is subject to change if you update to a newer release of WebLogic Server. Invoking this operation isolates this MBean from the effects of such changes.

Note: To insure that you are freezing the default value, invoke the restoreDefaultValue operation before you invoke this.

This operation has no effect if you invoke it on an attribute that does not provide a default value or on an attribute for which some other value has been set.

Deprecated. 9.0.0.0

getInheritedProperties

Return all properties' names whose value is inherited from template mbean. this is a convenient method to get inheritance info on multiple properties in one jmx call.

isInherited

Check if the value of a property is inherited from template mbean or not.

isSet

Returns true if the specified attribute has been set explicitly in this MBean instance.

removeTag

Remove a tag from this Configuration MBean

removeTarget

Untargets a server instance from a store.

restoreDefaultValue

If the specified attribute has a default value, this operation removes any value that has been set explicitly and causes the attribute to use the default value.

Default values are subject to change if you update to a newer release of WebLogic Server. To prevent the value from changing if you update to a newer release, invoke the freezeCurrentValue operation.

This operation has no effect if you invoke it on an attribute that does not provide a default value or on an attribute that is already using the default.

Deprecated. 9.0.0.0

unSet

Restore the given property to its default value.