A JE Backend stores application data in a Berkeley DB Java Edition database.
It is the traditional "directory server" backend and is similar to the backends provided by the Sun Java System Directory Server. The JE Backend stores the entries in an encoded form and also provides indexes that can be used to quickly locate target entries based on different kinds of criteria.
Advanced Properties
db-checkpointer-bytes-interval
Synopsis | Specifies the maximum number of bytes that may be written to the database before it is forced to perform a checkpoint. |
Description | This can be used to bound the recovery time that may be required if the database environment is opened without having been properly closed. If this property is set to a non-zero value, the checkpointer wakeup interval is not used. To use time-based checkpointing, set this property to zero. |
Default Value | 500mb
|
Allowed Values | A positive integer representing a size. Upper limit: 9223372036854775807. |
Multi-valued | No |
Required | No |
Admin Action Required | Restart the server for changes to take effect. |
Advanced | Yes |
Read-Only | No |
db-checkpointer-wakeup-interval
Synopsis | Specifies the maximum length of time that may pass between checkpoints. |
Description | Note that this is only used if the value of the checkpointer bytes interval is zero. |
Default Value | 30s
|
Allowed Values | A duration. Lower limit: 1 seconds. Upper limit: 4294 seconds. |
Multi-valued | No |
Required | No |
Admin Action Required | The object must be disabled and re-enabled for changes to take effect. |
Advanced | Yes |
Read-Only | No |
db-cleaner-min-utilization
Synopsis | Specifies the occupancy percentage for "live" data in this backend's database. |
Description | When the amount of "live" data in the database drops below this value, cleaners will act to increase the occupancy percentage by compacting the database. |
Default Value | 50
|
Allowed Values | An integer. Lower limit: 0. Upper limit: 90. |
Multi-valued | No |
Required | No |
Admin Action Required | None |
Advanced | Yes |
Read-Only | No |
db-directory-permissions
Synopsis | Specifies the permissions that should be applied to the directory containing the server database files. |
Description | They should be expressed as three-digit octal values, which is the traditional representation for UNIX file permissions. The three digits represent the permissions that are available for the directory's owner, group members, and other users (in that order), and each digit is the octal representation of the read, write, and execute bits. Note that this only impacts permissions on the database directory and not on the files written into that directory. On UNIX systems, the user's umask controls permissions given to the database files. |
Default Value | 700
|
Allowed Values | Any octal value between 700 and 777 (the owner must always have read, write, and execute permissions on the directory). |
Multi-valued | No |
Required | No |
Admin Action Required | Restart the server for changes to take effect. |
Advanced | Yes |
Read-Only | No |
db-evictor-core-threads
Synopsis | Specifies the core number of threads in the eviction thread pool. |
Description | Specifies the core number of threads in the eviction thread pool. These threads help keep memory usage within cache bounds, offloading work from application threads. db-evictor-core-threads, db-evictor-max-threads and db-evictor-keep-alive are used to configure the core, max and keepalive attributes for the eviction thread pool. |
Default Value | 1
|
Allowed Values | An integer. Lower limit: 0. Upper limit: 2147483647. |
Multi-valued | No |
Required | No |
Admin Action Required | None |
Advanced | Yes |
Read-Only | No |
db-evictor-keep-alive
Synopsis | The duration that excess threads in the eviction thread pool will stay idle. After this period, idle threads will terminate. |
Description | The duration that excess threads in the eviction thread pool will stay idle. After this period, idle threads will terminate. db-evictor-core-threads, db-evictor-max-threads and db-evictor-keep-alive are used to configure the core, max and keepalive attributes for the eviction thread pool. |
Default Value | 600s
|
Allowed Values | A duration. Lower limit: 1 seconds. Upper limit: 86400 seconds. |
Multi-valued | No |
Required | No |
Admin Action Required | None |
Advanced | Yes |
Read-Only | No |
db-evictor-lru-only
Synopsis | Indicates whether the database should evict existing data from the cache based on an LRU policy (where the least recently used information will be evicted first). |
Description | If set to "false", then the eviction keeps internal nodes of the underlying Btree in the cache over leaf nodes, even if the leaf nodes have been accessed more recently. This may be a better configuration for databases in which only a very small portion of the data is cached. |
Default Value | false
|
Allowed Values | true false |
Multi-valued | No |
Required | No |
Admin Action Required | The object must be disabled and re-enabled for changes to take effect. |
Advanced | Yes |
Read-Only | No |
db-evictor-max-threads
Synopsis | Specifies the maximum number of threads in the eviction thread pool. |
Description | Specifies the maximum number of threads in the eviction thread pool. These threads help keep memory usage within cache bounds, offloading work from application threads. db-evictor-core-threads, db-evictor-max-threads and db-evictor-keep-alive are used to configure the core, max and keepalive attributes for the eviction thread pool. |
Default Value | 10
|
Allowed Values | An integer. Lower limit: 1. Upper limit: 2147483647. |
Multi-valued | No |
Required | No |
Admin Action Required | None |
Advanced | Yes |
Read-Only | No |
db-evictor-nodes-per-scan
Synopsis | Specifies the number of Btree nodes that should be evicted from the cache in a single pass if it is determined that it is necessary to free existing data in order to make room for new information. |
Description | Changes to this property do not take effect until the backend is restarted. It is recommended that you also change this property when you set db-evictor-lru-only to false. This setting controls the number of Btree nodes that are considered, or sampled, each time a node is evicted. A setting of 10 often produces good results, but this may vary from application to application. The larger the nodes per scan, the more accurate the algorithm. However, don't set it too high. When considering larger numbers of nodes for each eviction, the evictor may delay the completion of a given database operation, which impacts the response time of the application thread. In JE 4.1 and later, setting this value too high in an application that is largely CPU bound can reduce the effectiveness of cache eviction. It's best to start with the default value, and increase it gradually to see if it is beneficial for your application. |
Default Value | 10
|
Allowed Values | An integer. Lower limit: 1. Upper limit: 1000. |
Multi-valued | No |
Required | No |
Admin Action Required | The object must be disabled and re-enabled for changes to take effect. |
Advanced | Yes |
Read-Only | No |
db-log-file-max
Synopsis | Specifies the maximum size for a database log file. |
Default Value | 100mb
|
Allowed Values | A positive integer representing a size. Lower limit: 1000000. Upper limit: 4294967296. |
Multi-valued | No |
Required | No |
Admin Action Required | The object must be disabled and re-enabled for changes to take effect. |
Advanced | Yes |
Read-Only | No |
db-log-filecache-size
Synopsis | Specifies the size of the file handle cache. |
Description | The file handle cache is used to keep as much opened log files as possible. When the cache is smaller than the number of logs, the database needs to close some handles and open log files it needs, resulting in less optimal performances. Ideally, the size of the cache should be higher than the number of files contained in the database. Make sure the OS number of open files per process is also tuned appropriately. |
Default Value | 100
|
Allowed Values | An integer. Lower limit: 3. Upper limit: 2147483647. |
Multi-valued | No |
Required | No |
Admin Action Required | The object must be disabled and re-enabled for changes to take effect. |
Advanced | Yes |
Read-Only | No |
db-logging-file-handler-on
Synopsis | Indicates whether the database should maintain a je.info file in the same directory as the database log directory. |
Description | This file contains information about the internal processing performed by the underlying database. |
Default Value | true
|
Allowed Values | true false |
Multi-valued | No |
Required | No |
Admin Action Required | The object must be disabled and re-enabled for changes to take effect. |
Advanced | Yes |
Read-Only | No |
db-logging-level
Synopsis | Specifies the log level that should be used by the database when it is writing information into the je.info file. |
Description | The database trace logging level is (in increasing order of verbosity) chosen from: OFF, SEVERE, WARNING, INFO, CONFIG, FINE, FINER, FINEST, ALL. |
Default Value | CONFIG
|
Allowed Values | A string. |
Multi-valued | No |
Required | No |
Admin Action Required | The object must be disabled and re-enabled for changes to take effect. |
Advanced | Yes |
Read-Only | No |
db-num-cleaner-threads
Synopsis | Specifies the number of threads that the backend should maintain to keep the database log files at or near the desired utilization. |
Description | In environments with high write throughput, multiple cleaner threads may be required to maintain the desired utilization. |
Default Value | Let the server decide. |
Allowed Values | An integer. Lower limit: 1. |
Multi-valued | No |
Required | No |
Admin Action Required | None |
Advanced | Yes |
Read-Only | No |
db-num-lock-tables
Synopsis | Specifies the number of lock tables that are used by the underlying database. |
Description | This can be particularly important to help improve scalability by avoiding contention on systems with large numbers of CPUs. The value of this configuration property should be set to a prime number that is less than or equal to the number of worker threads configured for use in the server. |
Default Value | Let the server decide. |
Allowed Values | An integer. Lower limit: 1. Upper limit: 32767. |
Multi-valued | No |
Required | No |
Admin Action Required | The object must be disabled and re-enabled for changes to take effect. |
Advanced | Yes |
Read-Only | No |
db-run-cleaner
Synopsis | Indicates whether the cleaner threads should be enabled to compact the database. |
Description | The cleaner threads are used to periodically compact the database when it reaches a percentage of occupancy lower than the amount specified by the db-cleaner-min-utilization property. They identify database files with a low percentage of live data, and relocate their remaining live data to the end of the log. |
Default Value | true
|
Allowed Values | true false |
Multi-valued | No |
Required | No |
Admin Action Required | None |
Advanced | Yes |
Read-Only | No |
db-txn-no-sync
Synopsis | Indicates whether database writes should be primarily written to an internal buffer but not immediately written to disk. |
Description | Setting the value of this configuration attribute to "true" may improve write performance but could cause the most recent changes to be lost if the OpenDJ directory server or the underlying JVM exits abnormally, or if an OS or hardware failure occurs (a behavior similar to running with transaction durability disabled in the Sun Java System Directory Server). |
Default Value | false
|
Allowed Values | true false |
Multi-valued | No |
Required | No |
Admin Action Required | None |
Advanced | Yes |
Read-Only | No |
db-txn-write-no-sync
Synopsis | Indicates whether the database should synchronously flush data as it is written to disk. |
Description | If this value is set to "false", then all data written to disk is synchronously flushed to persistent storage and thereby providing full durability. If it is set to "true", then data may be cached for a period of time by the underlying operating system before actually being written to disk. This may improve performance, but could cause the most recent changes to be lost in the event of an underlying OS or hardware failure (but not in the case that the OpenDJ directory server or the JVM exits abnormally). |
Default Value | true
|
Allowed Values | true false |
Multi-valued | No |
Required | No |
Admin Action Required | None |
Advanced | Yes |
Read-Only | No |
disk-full-threshold
Synopsis | Full disk threshold to limit database updates |
Description | When the available free space on the disk used by this database instance falls below the value specified, no updates are permitted and the server returns an UNWILLING_TO_PERFORM error. Updates are allowed again as soon as free space rises above the threshold. |
Default Value | 100 megabytes
|
Allowed Values | A positive integer representing a size. |
Multi-valued | No |
Required | No |
Admin Action Required | None |
Advanced | Yes |
Read-Only | No |
disk-low-threshold
Synopsis | Low disk threshold to limit database updates |
Description | Specifies the "low" free space on the disk. When the available free space on the disk used by this database instance falls below the value specified, protocol updates on this database are permitted only by a user with the BYPASS_LOCKDOWN privilege. |
Default Value | 200 megabytes
|
Allowed Values | A positive integer representing a size. |
Multi-valued | No |
Required | No |
Admin Action Required | None |
Advanced | Yes |
Read-Only | No |
entries-compressed
Synopsis | Indicates whether the backend should attempt to compress entries before storing them in the database. |
Description | Note that this property applies only to the entries themselves and does not impact the index data. Further, the effectiveness of the compression is based on the type of data contained in the entry. |
Default Value | false
|
Allowed Values | true false |
Multi-valued | No |
Required | No |
Admin Action Required | None Changes to this setting take effect only for writes that occur after the change is made. It is not retroactively applied to existing data. |
Advanced | Yes |
Read-Only | No |
import-offheap-memory-size
Synopsis | Specifies the amount of off-heap memory dedicated to the online operation (import-ldif, rebuild-index). |
Default Value | Use only heap memory. |
Allowed Values | A positive integer representing a size. |
Multi-valued | No |
Required | No |
Admin Action Required | None |
Advanced | Yes |
Read-Only | No |
index-entry-limit
Synopsis | Specifies the maximum number of entries that is allowed to match a given index key before that particular index key is no longer maintained. |
Description | This property is analogous to the ALL IDs threshold in the Sun Java System Directory Server. Note that this is the default limit for the backend, and it may be overridden on a per-attribute basis. A value of 0 means there is no limit. Changing the index entry limit significantly can result in serious performance degradation. Please read the documentation before changing this setting. |
Default Value | 4000
|
Allowed Values | An integer. Lower limit: 0. Upper limit: 2147483647. |
Multi-valued | No |
Required | No |
Admin Action Required | None If any index keys have already reached this limit, indexes need to be rebuilt before they are allowed to use the new limit. |
Advanced | Yes |
Read-Only | No |
index-filter-analyzer-enabled
Synopsis | Indicates whether to gather statistical information about the search filters processed by the directory server while evaluating the usage of indexes. |
Description | Analyzing indexes requires gathering search filter usage patterns from user requests, especially for values as specified in the filters and subsequently looking the status of those values into the index files. When a search requests is processed, internal or user generated, a first phase uses indexes to find potential entries to be returned. Depending on the search filter, if the index of one of the specified attributes matches too many entries (exceeds the index entry limit), the search becomes non-indexed. In any case, all entries thus gathered (or the entire DIT) are matched against the filter for actually returning the search result. |
Default Value | false
|
Allowed Values | true false |
Multi-valued | No |
Required | No |
Admin Action Required | None |
Advanced | Yes |
Read-Only | No |
index-filter-analyzer-max-filters
Synopsis | The maximum number of search filter statistics to keep. |
Description | When the maximum number of search filter is reached, the least used one will be deleted. |
Default Value | 25
|
Allowed Values | An integer. Lower limit: 1. |
Multi-valued | No |
Required | No |
Admin Action Required | None |
Advanced | Yes |
Read-Only | No |
java-class
Synopsis | Specifies the fully-qualified name of the Java class that provides the backend implementation. |
Default Value | org.opends.server.backends.jeb.JEBackend
|
Allowed Values | A Java class that extends or implements: org.opends.server.api.Backend |
Multi-valued | No |
Required | Yes |
Admin Action Required | The object must be disabled and re-enabled for changes to take effect. |
Advanced | Yes |
Read-Only | No |
je-property
Synopsis | Specifies the database and environment properties for the Berkeley DB Java Edition database serving the data for this backend. |
Description | Any Berkeley DB Java Edition property can be specified using the following form: property-name=property-value. Refer to OpenDJ documentation for further information on related properties, their implications, and range values. The definitive identification of all the property parameters is available in the example.properties file of Berkeley DB Java Edition distribution. |
Default Value | None |
Allowed Values | A string. |
Multi-valued | Yes |
Required | No |
Admin Action Required | None |
Advanced | Yes |
Read-Only | No |
preload-time-limit
Synopsis | Specifies the length of time that the backend is allowed to spend "pre-loading" data when it is initialized. |
Description | The pre-load process is used to pre-populate the database cache, so that it can be more quickly available when the server is processing requests. A duration of zero means there is no pre-load. |
Default Value | 0s
|
Allowed Values | A duration. Lower limit: 0 milliseconds. Upper limit: 2147483647 milliseconds. |
Multi-valued | No |
Required | No |
Admin Action Required | None |
Advanced | Yes |
Read-Only | No |