Chapter 15. List of Configuration Properties

General Configuration Properties
Worker - Configuration Properties
Worker - JNDI Properties
Worker - SSL Properties
Job Execution Properties

Below you can find the configuration properties available in CloverDX Server. The essential properties can be configured using the Setup GUI. Other properties serve to tweak various features of CloverDX Server. However, these properties have to be configured manually, e.g. by editing the configuration file.

In CloverDX Server UI, you can view the properties and their values in Configuration > CloverDX Info > Server Properties.

Additional properties used for cluster configuration can be found in Chapter 41, Sandboxes in Cluster.


Configuration property and system property are not the same. Configuration properties can be configured in Setup section or in file. System properties serve to configure the JVM. E.g. in Apache Tomcat, they are configured in bin/setenv.[bat|sh] file using -D prefix.

General Configuration Properties

Configuration file
Database connection
Thread Manager
Properties resolver
Data Services

Table 15.1. General configuration

KeyDescriptionDefault Value
clover.config.file Absolute path to location of a CloverDX Server configuration file /absolute/path/to/

By default, this property is commented out and has a dynamically computed value: path containing CloverETL value for current (pre 5.0) installations and CloverDX for new (5.0 and newer) installations.

If defined by the user, value has a higher priority.

The property can be overridden using:

environment variable clover.clover.home

context parameter <Parameter name="clover.home">

or system property -Dclover.clover.home=

${}/CloverETL or ${}/CloverDX
license.file Absolute path to location of a CloverDX Server license file (license.dat)  
license.context_names A comma-separated list of web-app contexts which may contain license. Each of them has to start with a slash! Works only on Apache Tomcat. /clover-license,/clover_license
engine.config.filelocation of a CloverDX engine configuration properties fileproperties file packed with CloverDX
engine.plugins.additional.src This property may contain an absolute path to some "source" of additional CloverDX engine plugins. These plugins are not a substitute for plugins packed in WAR. "Source" may be a directory or a zip file. Both, a directory and a zip, must contain a subdirectory for each plugin. Changes in the directory or the ZIP file apply only when the server is restarted. For details see Chapter 34, Extensibility - CloverDX Engine Plugins. empty

This property is primarily intended to be used as a placeholder in the sandbox root path specification. So the sandbox path is specified with the placeholder and it's resolved to the real path just before it's used. The sandbox path may still be specified as an absolute path, but placeholder has some significant advantages:

* sandbox definition may be exported/imported to another environment with a different directory structure

* user creating sandboxes doesn't have to care about physical location on the filesystem

* each node in cluster environment may have a different "sandboxes.home" value, so the directory structure doesn't have to be identical

For backward compatibility, the default value uses the content of the clover.home configuration property.


true | false If it is set to false, then the path relative to a sandbox root may point out of the sandbox. No file/folder outside of the sandbox is accessible by the relative path otherwise.

Database connection
datasource.type Set this explicitly to JNDI if you need CloverDX Server to connect to a DB using JNDI datasource. In such case, "datasource.jndiName" and "jdbc.dialect" parameters must be set properly. Possible values: JNDI | JDBC JDBC
datasource.jndiName JNDI location of a DB DataSource. It is applied only if "datasource.type" is set to "JNDI". java:comp/env/jdbc/clover_server
jdbc.driverClassName class name for JDBC driver name 
jdbc.urlJDBC URL used by CloverDX Server to store data 
jdbc.usernameJDBC database user name 
jdbc.passwordJDBC database password 
jdbc.dialecthibernate dialect to use in ORM 
quartz.driverDelegateClass SQL dialect for quartz. Value is automatically derived from "jdbc.dialect" property value.  
Security List of server properties which are used only by the CloverDX Server code. So these properties are not accessible outside of the ServerFacade. By default, there are all properties which may contain password in the list, so their values are not visible for web GUI users. The values are replaced by a single star "*". Changes in this list may cause unexpected behavior of some server API. jdbc.password, executor.password, security.ldap.password, clover.smtp.password
security.session.validitySession validity in milliseconds. When the request of logged-in user/client is detected, validity is automatically prolonged.14400000 for exchange of invalid tokens in milliseconds.360000
security.default_domainDomain in which all new users are included. Stored in user's record in the database. Shouldn't be changed unless the "clover" must be white-labelled.clover

List of features which are accessible using HTTP and which should be protected by Basic HTTP Authentication. The list has form of semicolon separated items; Each feature is specified by its servlet path.


Realm string for HTTP Basic Authentication.

CloverDX Server

List of features which are accessible using HTTP and which should be protected by HTTP Digest Authentication. The list has form of semi-colon separated items. Each feature is specified by its servlet path.

Please keep in mind that HTTP Digest Authentication is feature added to the version 3.1. If you upgraded your older CloverDX Server distribution, users created before the upgrade cannot use the HTTP Digest Authentication until they reset their passwords. So when they reset their passwords (or the admin does it for them), they can use Digest Authentication as well as new users.

security.digest_authentication.storeA1.enabled Switch whether the A1 Digest for HTTP Digest Authentication should be generated and stored or not. Since there is no CloverDX Server API using the HTTP Digest Authentication by default, it's recommended to keep it disabled. This option is not automatically enabled when any feature is specified in the security.digest_authentication.features_list property. false
security.digest_authentication.realm Realm string for HTTP Digest Authentication. If it is changed, all users have to reset their passwords, otherwise they won't be able to access the server features protected by HTTP digest Authentication. CloverDX Server
security.digest_authentication.nonce_validity Interval of validity for HTTP Digest Authentication specified in seconds. When the interval passes, server requires new authentication from the client. Most of the HTTP clients do it automatically. 300
security.lockout.login.attempts The number of failed login attempts after which a next failed login attempt will lock the user. Set the value to 0 to disable the function. Since 4.8.0M1. 50
security.lockout.reset.period Period of time in seconds during which the failed login attempts are counted. Since 4.8.0M1. 60
security.lockout.unlock.period Period of time in seconds after which a successful login attempt will unlock the previously locked user. Since 4.8.0M1. 300

Enable/disable protection of Simple HTTP API against CSRF attacks, enabled by default. The CSRF protection requires presence of the X-Requested-By header in the requests.

For more details, see the section called “CSRF Protection”.

clover.smtp.transport.protocolSMTP server protocol. Possible values are "smtp" or "smtps".smtp
clover.smtp.hostSMTP server hostname or IP address 
clover.smtp.portSMTP server port 
clover.smtp.authenticationtrue/false If it is false, username and password are ignored. 
clover.smtp.usernameSMTP server username 
clover.smtp.passwordSMTP server password 
clover.smtp.additional.* Properties with a "clover.smtp.additional." prefix are automatically added (without the prefix) to the Properties instance passed to the Mailer. May be useful for some protocol specific parameters. The prefix is removed. 
logging.project_nameUsed in log messages where it is necessary to name the product name.CloverDX
logging.default_subdir Name of a default subdirectory for all server logs; it is relative to the path specified by system property "". Don't specify as an absolute path, use properties which are intended for absolute path. cloverlogs
logging.logger.server_audit.enabled Enables logging of operations called on ServerFacade and JDBC proxy interfaces. The name of the output file is "server-audit.log". It is stored in the same directory as other CloverDX Server log files by default. The default logging level is DEBUG so it logs all operations which may process any change. false
logging.logger.server_integration.enabled Enables logging of Designer-Server calls. The name of the output file is "server-integration.log". It is stored in the same directory as other CloverDX Server log files by default. The default logging level is INFO. Username is logged, if available. JDBC and CTL debugging is not logged. true
launch.log.dir Location, where server should store launch requests logs. See Chapter 39, Launch Services for details. ${}/[logging. default_subdir]/launch where ${} is system property
graph.logs_path Location, where server should store Graph run logs. See Chapter 17, Logging for details. ${}/[logging. default_subdir]/graph where ${} is system property Pattern of the jobs' log messages %d %-5p %-3X{runId} [%t] %m%n of the jobs' log filesUTF-8

Format of log that can be seen in Monitoring > Logs > Worker.


Size of log that can be seen in Monitoring > Logs > Worker.

Thread Manager

Number of threads which are always active (running or idling). Related to a thread pool for processing server events.


Max size of the queue (FIFO) which contains tasks waiting for an available thread. Related to a thread pool for processing server events. For queueCapacity=0, there are no waiting tasks, each task is immediately executed in an available thread or in a new thread.


Max number of active threads. If no thread from a core pool is available, the pool creates new threads up to "maxPoolSize" threads. If there are more concurrent tasks then maxPoolSize, thread manager refuses to execute it.


Switch for idling threads timeout. If true, the "corePoolSize" is ignored so all idling threads may be time-outed


timeout for idling threads in seconds

task.archivator.batch_size Max number of records deleted in one batch. It is used for deleting of archived run records. 50
task.archivator.archive_file_prefix Prefix of archive files created by the archivator. cloverArchive_
Properties resolver
properties_resolver.resolve_server_props.server_props_list_additional A list of properties from a subset of properties, which values are resolved. The properties' values may use system properties or environment variables as placeholders. The values are resolved during the server startup. If the system property is changed later, the resolved CloverDX Server property value doesn't change. Users may use this property, if some property they need to resolve is missing in the property: properties_resolver.resolve_server_props.server_props_list_default. If the property to resolve is already specified by the property properties_resolver.resolve_server_props.server_props_list_default, don't add it to this property.  
properties_resolver.resolve_server_props.server_props_list_default A list of properties from a subset of properties, which values are resolved. The properties' values may use system properties or environment variables as placeholders. Values are resolved during the server startup. If the system property is changed later, the resolved CloverDX Server property value doesn't change. Users are discouraged from modification of the property, unless it's necessary. Instead, users may add more properties by modifying property: properties_resolver.resolve_server_props.server_props_list_additional clover.home, sandboxes.home, sandboxes.home.local, sandboxes.home.partitioned, cluster.jgroups.bind_address, cluster.jgroups.start_port, cluster.jgroups.external_address, cluster.jgroups.external_port, cluster.jgroups.tcpping.initial_hosts,, cluster.http.url
properties_resolver.placeholders.server_props_list_default A list of properties from a subset of properties, that may be used as placeholders and shall be resolved if used in paths. The properties can be used if you define a path to the root of a sandbox, or to locations of local or partitioned sandboxes, or path to a script, or path in archiver job. Users are strongly discouraged from modification of the property. The property name changed since CloverDX 4.2, however the obsolete name is also still accepted to maintain backwards compatibility. clover.home, sandboxes.home, sandboxes.home.local, sandboxes.home.partitioned,
Data Services
dataservice.invocation.record.max.age It sets the maximal age in minutes before the record is removed from the database. The default is 1440 min = 24 h. 1440
dataservice.failure.ratio.min.record.count Used for Data Service failure indication. It represents the minimum number of invocations required to evaluate whether the percentage of failures is over the threshold. Ensures that during periods of low traffic the endpoint does not switch to failing state. 10 by default. 10
launch.http_header_prefixPrefix of HTTP headers added by launch services to the HTTP response.X-cloveretl

Enables or disables simple HTTP API.

If the HTTP API is disabled, there is no link to HTTP API operations in login page, the HTTP API tab in Launch Service that is accessible under Test button is not visible, and the HTTP API, the /clover/httpapi.jsp and HTTP API servlet are not accessible.

Available since 4.8.0M1. See Chapter 36, Simple HTTP API.


Maximum depth for webDAV method PROPFIND. When the depth is not specified, the default is supposed to be infinite (according to the rfc2518), however it's necessary to set some limit, otherwise the webDav client might overload the server filesystem.

Also if the depth value specified by webDAV client in the request is higher than the pre-configured max depth, only the pre-configured maximum is used.

server.env.min_heap_memory Sets the required minimal heap memory threshold. If the configuration of CloverDX Server is set to less heap memory, a warning is displayed. Experienced users can change the default value to avoid the warning when running the server on a system with lower memory. The threshold is in megabytes. 900
server.env.min_nonheap_memory Sets the required minimal non-heap memory threshold. If the configuration of CloverDX Server is set to less non-heap memory, a warning is displayed. Experienced users can change the default value to avoid the warning when running the server on a system with lower memory. The threshold is in megabytes. 256
jvm.implementation.check.enabled Displays warnings when unsupported Java implementation is used.true
temp.default_subdirName of a default subdirectory for server tmp files; it is relative to the path specified by system property "".clovertmp
graph.pass_event_params_to_graph_in_old_style Since 3.0. It is a switch for backwards compatibility of passing parameters to the graph executed by a graph event. In versions prior to 3.0, all parameters are passed to executed graph. Since 3.0, just specified parameters are passed. Please see Start a Graph for details. false Sets the interval for synchronization of the Data Services health state between the cluster nodes. The time is in milliseconds. 30000
clover.event.fileCheckMinInterval Interval of the timer, running file event listener checks (in milliseconds). See File Event Listeners (remote and local) for details. 1000
clover.event.groovyCheckMinInterval 1000
clover.inDevelopment 1000
launchservices.visible Display Launch Services in the main menu in Server UI. Can be true or false. false

Worker - Configuration Properties

Table 15.2. Server - Worker configuration

KeyDescriptionDefault Value

Enable/disable the Worker. To enable Worker, set to 1 (this is the default). To disable Worker and run all jobs in Core Server, set to 0.

Starting more than one Worker is currently (in 4.9.0) not supported.


Port range used for communication between Server Core and Worker and between Workers on different cluster nodes. Communication between Server Core and Worker is done on localhost. Workers on different cluster nodes communicate directly with each other over these ports - in Cluster setup, this port range should be open in firewall for other Cluster nodes.

This property can be easily configured in the Worker tab of Setup.

worker.portRange should contain at least 5 ports for 1 node (depending on other options, a node takes at most 5 ports from the range). We recommend to use portRange of at least 10 ports to avoid possible problems with occupied ports after restart of Worker.

If more cluster nodes run on the same machine, make sure that there are enough free ports for Workers of all cluster nodes on the machine. The default configuration of worker.portRange is sufficient for that.


Timeout for connection initialization between Worker and Server Core, in both directions. The timeout is in milliseconds.

This setting can be useful in case of handling communication issues between Server Core and Worker, typically under high load you might want to increase the timeout.


Read timeout for communication requests between Worker and Server Core, in both directions. If a request is not completely served before reaching this limit, the connection is terminated. The timeout is in milliseconds.

This setting can be useful in case of handling communication issues between Server Core and Worker, typically under high load you might want to increase the timeout.


A directory with additional .jar files to be added to the Worker's classpath. The .jar files would typically be libraries used by graphs (e.g. JDBC drivers for database connections) or JDBC drivers used in JNDI connections defined in Worker (see Worker - JNDI Properties).

The Worker's classpath is separate from Server Core (i.e. application container classpath). Any libraries needed by jobs executed on Worker need to be added on the Worker's classpath.

For backward compatibility, the default value uses the content of the clover.home configuration property.

The property can contain paths to multiple directories. The separator between the directories can be a colon (on Linux and Mac) or semicolon (Linux, Mac and Windows), e.g.:


If a directory is added on the Worker's classpath, its subdirectories are automatically added too.

Some basic wildcards are supported: directory-* and directory-?.


The maximum Java heap size of Worker in MB, it will be translated to the -Xmx option for the Worker's JVM. Jobs executed in the Worker require heap memory based on their complexity, dataset size, etc.

See our recommendations for heap sizes of Worker and Server Core.

This property can be easily configured in the Worker tab of Setup.

Setting to 0 uses Java default heap size (automatically determined by Java). This setting is not recommended for production usage.


The initial Java heap size of Worker in MB, it will be translated to the -Xms option for the Worker's JVM. We recommend to set this to the same value as worker.maxHeapSize

This property can be easily configured in the Worker tab of Setup.

Setting to 0 uses Java default initial heap size (automatically determined by Java). This setting is not recommended for production usage.


Adds Java command line options for the Worker's JVM. This property is useful to tweak the configuration of the Worker's JVM, e.g. to tune garbage collector settings. These command line options override default options of the JVM.

For example to enable parallel garbage collector: -XX:+UseParallelGC.

See Additional Diagnostic Tools section for useful options for troubleshooting and debugging Worker.

This property can be easily configured in the Worker tab of Setup.

worker.enableDebug Remote Java debugging of Worker, enables JDWP. Enabling this allows you to connect a Java debugger remotely to the running Worker process, to debug your Java transformations, investigate issues, etc. The port used by the debugger is determined dynamically and can be seen in the Worker section of the Monitoring page. false

Sets whether system Java properties are inherited from the Server Core process to the Worker process. We automatically inherit some system properties to simplify the Worker configuration, see below for a list.

This functionality is enabled by default. Use this property to disable this behavior in case some of the inherited properties would cause issues.

The following system Java properties are inherited from the Server Core to Worker:

# Clover properties
com.opensys.cloveretl.addressdoctor.setConfigFile, com.opensys.cloveretl.addressdoctor.persistent

# Standard Java properties

# SSL related properties,,

# Proxy configuration
*.proxyHost, *.proxyPort, *.proxyUser, *.proxyPassword, *.nonProxyHosts
socksProxyHost, socksProxyPort, socksProxyVersion,,,

Absolute path to the Java binary for Worker process, e.g. /user/local/java/bin/java.

Use this property if you need to use a specific Java binary for running the Worker.

Value is automatically determined based on $JAVA_HOME environment variable.

Worker - JNDI Properties

The Worker has its own JNDI pool separate from the application container JNDI pool. If your jobs use JNDI resources (to obtain JDBC or JMS connections), you have to configure the Worker's JNDI pool and its resources.

The worker JNDI properties must be configured using the configuration file. Libraries used by the JNDI resources must be added to the Worker's classpath, see worker.classpath.

It is possible to define multiple datasources pointing to different databases or JMS queues, see examples below. The datasources are indexed in configuration, their properties have suffix [0], [1], etc. Even a single datasource must have the [0] index.

JDBC Datasources

Worker uses the Apache DBCP2 pool for its JNDI functionality. Any DBCP2 configuration attribute is supported, see DBCP attributes. The only mandatory properties are jndiName and url.

See table below for basic JNDI properties.

You can monitor the state of the datasources via JMX. See Additional Diagnostic Tools for details on how to enable JMX on Worker. Then you can connect to the Worker's JMX interface with tools like jconsole and monitor the JNDI datasources, e.g. for the number of currently open connections. The related MBeans are under the Tomcat/DataSource/localhost///javax.sql.DataSource path:

MBean for a JNDI datasource in jconsole

Figure 15.1. MBean for a JNDI datasource in jconsole

Table 15.3. Properties for JDBC JNDI Resources in Worker

worker.jndi.datasource[0].jndiName The name of the JNDI datasource. Mandatory. jdbc/database_name
worker.jndi.datasource[0].url The JDBC connection URL. Mandatory. jdbc:postgresql://hostname:5432/database_name
worker.jndi.datasource[0].username The user name for a database connection. clover
worker.jndi.datasource[0].password The password for a database connection. The password value can be encrypted using the secure configuration tool, see Secure Configuration Properties. clover
worker.jndi.datasource[0].driverClassName The database driver classname. The database driver must be on the Worker classpath, see worker.classpath. org.postgresql.Driver
worker.jndi.datasource[0].maxIdle The maximum number of idle database connections in a pool. Set to -1 for no limit. 10
worker.jndi.datasource[0].maxTotal The maximum number of database connections in a pool. Set to -1 for no limit. 20
worker.jndi.datasource[0].maxWaitMillis The maximum time Worker waits for a database connection to become available. In milliseconds, set to -1 for no limit. 30000
worker.jndi.datasource[0].dbcpAttribute Any DBCP2 attribute, e.g. worker.jndi.datasource[0].initSQL. See DBCP attributes.  

The following example shows configuration of two JDBC Datasources.



JMS Connections

Worker can use any JMS broker to define JMS connections in JNDI. Any JMS broker configuration attribute is supported. The mandatory properties are jndiName,factoryClass,typeClass and typeInterface. See table below for basic JNDI properties for JMS resources.

Table 15.4. Properties for JMS JNDI Resources in Worker

worker.jndi.jms[0].jndiName The name of the JNDI JMS resource. Mandatory. jms/jms_queue
worker.jndi.jms[0].factory Factory class for creating the JMS resource. This is JMS broker specific. Mandatory. org.apache.activemq.jndi.JNDIReferenceFactory
worker.jndi.jms[0].type Implementation class of the JMS resource. This is JMS broker specific. Mandatory. org.apache.activemq.command.ActiveMQQueue
worker.jndi.jms[0].jmsProperty Configuration property for the JMS resource. Any configuration property supported by the JMS broker can be used. worker.jndi.jms[0].brokerUrl.

The following example shows configuration of several JMS resources.



Worker - SSL Properties

In Cluster, Workers of each node communicate with each other directly for increased performance. This communication is used to transport data of cluster remote edges in clustered jobs between the nodes. For increased security, it is possible to use SSL for the remote edge communication.

SSL communication between Workers needs to be enabled and configured separately from SSL of the application container that runs Server Core. The worker.ssl.enabled property is used to enable/disable SSL. If a Cluster node's "self" URL is using HTTPS, we automatically set the property to true. Configuration of SSL consists of setting paths and passwords of KeyStore and TrustStore, see the table below for details.

Note that if the standard SSL related system properties (,,, and are used to configure KeyStore/TrustStore for the Server Core, they are propagated to Worker; therefore, their respective worker.ssl properties do not need to be configured.

Recommended steps to enable SSL for inter-worker communication are:

  • Enable SSL for each cluster node, via the application container settings. Configure TrustStore and KeyStore via the standard* properties.

  • Set cluster.http.url for each node to point to its own HTTPS URL

  • Check that communication between Cluster nodes over SSL works and that the nodes can correctly see each other. The Monitoring page of Server Console should show the whole cluster group and its nodes correctly.

  • Worker should automatically inherit the above SSL configuration.

  • Run a clustered job on Worker

Table 15.5. Properties for SSL communication in Worker


Enables or disables an SSL connection for Worker. Note that if the Server runs on HTTPS, SSL is enabled automatically; however, this property has a higher priority.

worker.ssl.keyStoreAbsolute path to the KeyStore file.path/to/keyStore.file
worker.ssl.keyStorePassword The KeyStore password. 

The alias of the key in keyStore. Optional - the property does not have to be specified if there is only one key in the KeyStore.

worker.ssl.port The port for SSL communication with Worker. The property is configured automatically and the value is set from worker.portRange.  
cluster.ssl.disableCertificateValidation Disables validation of certificates in HTTPS connections of remote edges. Disabling the validation affects jobs run on both Worker and Server Core. true/false

Job Execution Properties

Table 15.6. Defaults for job execution configuration - see Job Config Properties for details

KeyDescriptionDefault Value
executor.tracking_interval An interval in milliseconds for scanning of a current status of a running graph. The shorter interval, the bigger log file. 2000
executor.log_levelLog level of graph runs. TRACE | DEBUG | INFO | WARN | ERRORINFO
executor.max_job_tree_depth Defines maximal depth of the job execution tree, e.g. for recursive job it defines the maximal level of recursion (counting from root job). 32
executor.max_running_concurrently Amount of graph instances which may exist (or run) concurrently. 0 means no limits. 0

Specifies how long can a graph instance be idling before it is released from memory. Interval is in milliseconds. 0 means no caching.

This property has been renamed since 2.8. Original name was executor.maxGraphInstanceAge

executor.classpath Classpath for transformation/processor classes used in the graph. Directory [Sandbox_root]/trans/ does not have to be listed here, since it is automatically added to a graph run classpath.  
executor.skip_check_config Disables check of graph configuration. Increases performance of a graph execution; however, it may be useful during graph development. true
executor.password This property is deprecated. The password for decoding encoded DB connection passwords.  
executor.verbose_mode If true, more descriptive logs of graph runs are generated. true
executor.use_jmx If true, the graph executor registers JMX mBean of the running graph. true
executor.debug_mode If true, edges with enabled debug store data into files in debug directory. false

List of all properties