MMTE Client VMARG System Variables¶
There is a special group of system variables. They allow to transfer any number of additional options to MMTE Client executable file as Java Virtual Machine (JVM) arguments (VMARG).
Make sure each VMARG system variable is written one per line, with numbering.
All VMARG system variables must be consecutively enumerated with decimal numbers starting with 1 without interruption. For example, this is the valid sequence:
1, 2, 3, 4, 5
The following sequences are all invalid and will raise errors:
0, 1, 2, 3
1, 2, 4, 5
2, 3, 4, 5
4, 3, 2, 1
The general format of a VMARG system variable is as follows:
vmarg.N=-varname[=varvalue]
where
| Parameter | Description | Example |
|---|---|---|
| N | consecutive number of a VMARG system variable | 1 |
| varname | the system variable name | Dfile.encoding |
| varvalue | optional value of the system variable | utf8 |
The sample list of VMARG variables:
vmarg.1=-Xms128m
vmarg.2=-Xmx1024m
vmarg.3=-XX:StringTableSize=100007
vmarg.4=-Dfile.encoding=utf8
| VMARG Variable Name | Value? | Default Value | Description |
|---|---|---|---|
| Xms | Y | 128m | Limits amount of memory allocated for MMTE Client. "m" stands for Megabytes, "g" for Gigabytes. Works similar to MMS args You can track the initial and current memory size allocated for MMC in its status bar. |
| Xmx | Y | 1024m | |
| classpath | Y | lib\*.jar | There can be any number of [classpath](https://docs.oracle.com/javase/8/docs/technotes/tools/windows/classpath.html) variables. Additional Java libraries in jar format are expected there. Read also about Djava.library.path |
| XX:StringTableSize | Y | 100007 | JVM parameter for storing string data. If you load too huge amounts of data in MMC and you experience slowing down its performance, increase this value. |
| Dfile.encoding | Y | utf8 | If MMTE cannot determine encoding of some external file loaded, we assume that this file is encoded using this parameter. |
| Dlogback.configurationFile | Y | MetaMiner. logback.xml |
LOGBack configuration file for format details. It can include a path. |
| XX:- OmitStackTraceInFastThrow |
N | JVM flag for disabling completely the use of preallocated exceptions. | |
| agentlib:jdwp | Y | transport=dt_socket, server=y, suspend=n, address=5006 |
JVM parameters for remote access to MetaMiner Client java process. |
| Dcom.sun.management. jmxremote |
N | JVM parameters for remote access to MMTE Client Java process using the Java Management Extensions (JMX) technology. Disabled by default. It can be reasonable for debug purposes only. It is strongly recommended not to enable remote access for security reasons. |
|
| Dcom.sun.management. jmxremote.port |
Y | 8086 | |
| Dcom.sun.management. jmxremote.ssl |
Y | false | |
| Dcom.sun.management. jmxremote.authenticate |
Y | false | |
| XX:+ HeapDumpOnOutOfMemoryError |
N | JVM flag for dumping heap to the working directory on out-of-memory error. | |
| Djava.library.path | Y | lib\mu\64 | Directory (relational path) where additional dynamic link libraries (DLL) are located. Read also about classpath variables. |
| XX:+ PrintGC |
N | Activates the simple garbage collection (GC) logging mode, which prints a line for every young generation GC and every full GC. | |
| XX:+ PrintGCDetails |
N | Activates the detailed garbage collection (GC) logging mode, which differs depending on the GC algorithm used. | |
| XX:+ PrintHeapAtGC |
N | With this option, three memory addresses for each heap region are printed in the GC logs: lower address of the reserved memory region; current pointer to the top of the allocated area; upper bound of the reserved memory region. | |
| XX:+ PrintGCDateStamps |
N | Adds the date and time of the log entry to the beginning of each line. | |
| XX:+ PrintGCTimeStamps |
N | Adds a timestamp to every line of the log detailing the time passed (in seconds) since the JVM was started. | |
| XX:- PrintTenuringDistribution |
N | Adds extra GC event detail. | |
| XX:- PrintAdaptiveSizePolicy |
N | Adds details about the G1 (Garbage First) ergonomics to each of events. This provides an insight into Collection Set selection and pause time estimates. | |
| XX:+ UseGCLogFileRotation |
N | Enables GC log file rotation (automatic limitation and archiving). | |
| XX: NumberOfGCLogFiles |
Y | 40 | Limits the maximum number of archived log files. |
| XX: GCLogFileSize |
Y | 10M | Limits the maximum size of a single log file (Megabytes). |
| Xloggc | Y | %APPDATA%\metaminer\logs\gc-%t.log | Log file path & name mask. %t will be replaced with a timestamp. Note: colon ":" must be used instead of "=", for example: vmarg.19=-Xloggc:%APPDATA%\metaminer\logs\gc-%t.log |