org.perfcake.agent

Class PerfCakeAgent

java.lang.Object

org.perfcake.agent.PerfCakeAgent

public class PerfCakeAgent
extends Object

Java implementation of a PerfCake agent that can be used to monitor tested system's JVM.

Starts a thread with a socket server listening on a specified host and port and is used by PerfCake's reporting (class org.perfcake.reporting.reporters.MemoryUsageReporter) to gather memory usage data and to control garbage collection and heap dump activities needed by the reporter.

To attach the agent to the tested system's JVM, append the following JVM argument to the executing java command or use JAVA_OPTS environment variable:

"... -javaagent:<perfcake_jar_path>=hostname=<hostname>,port=<port>

where perfcake_jar_path is a path to PerfCake JAR archive, hostname and port specifies agent's socket.

Command	Description
"FREE"	Returns the amount of free memory in the Java Virtual Machine.
"USED"	Returns the amount of used memory in the Java Virtual Machine.
"TOTAL"	Returns the amount of total memory in the Java Virtual Machine.
"MAX"	Returns the maximum amount of memory that the Java Virtual Machine will attempt to use.
"DUMP(:<dump-file>)"	Initiates a heap dump into dump-file. dump-file is optional - if not provided, the file name would be generated as "dump-" + System.currentTimeMillis() + ".bin".
"GC"	Calls System.gc().

Author:

Pavel Macík

See Also:

AgentCommand

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_ENCODING Default encoding of the input and output streams.
static int	DEFAULT_PORT Default agent port.

Constructor Summary

Constructors

Constructor and Description
PerfCakeAgent()

Method Summary

Modifier and Type	Method and Description
static void	premain(String agentArgs) PerfCakeAgent's pre-main method.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_ENCODING

public static final String DEFAULT_ENCODING

Default encoding of the input and output streams.

See Also:

Constant Field Values

DEFAULT_PORT

public static final int DEFAULT_PORT

Default agent port.

See Also:

Constant Field Values

Constructor Detail

PerfCakeAgent

public PerfCakeAgent()

Method Detail

premain

public static void premain(String agentArgs)

PerfCakeAgent's pre-main method.

Parameters:

agentArgs - Agent arguments.

See Also:

java.lang.instrument