1jstatd(1)                      Monitoring Tools                      jstatd(1)
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NAME

6       jstatd - Monitors Java Virtual Machines (JVMs) and enables remote
7       monitoring tools to attach to JVMs. This command is experimental and
8       unsupported.
9

SYNOPSIS

11       jstatd [ options ]
12
13
14       options
15              The command-line options. See Options.
16

DESCRIPTION

18       The jstatd command is an RMI server application that monitors for the
19       creation and termination of instrumented Java HotSpot VMs and provides
20       an interface to enable remote monitoring tools to attach to JVMs that
21       are running on the local host.
22
23       The jstatd server requires an RMI registry on the local host. The
24       jstatd server attempts to attach to the RMI registry on the default
25       port, or on the port you specify with the -pport option. If an RMI
26       registry is not found, then one is created within the jstatd
27       application that is bound to the port that is indicated by the -pport
28       option or to the default RMI registry port when the -pport option is
29       omitted. You can stop the creation of an internal RMI registry by
30       specifying the -nr option.
31

OPTIONS

33       -nr
34              Does not attempt to create an internal RMI registry within the
35              jstatd process when an existing RMI registry is not found.
36
37       -p port
38              The port number where the RMI registry is expected to be found,
39              or when not found, created if the -nr option is not specified.
40
41       -n rminame
42              Name to which the remote RMI object is bound in the RMI
43              registry. The default name is JStatRemoteHost. If multiple
44              jstatd servers are started on the same host, then the name of
45              the exported RMI object for each server can be made unique by
46              specifying this option. However, doing so requires that the
47              unique server name be included in the monitoring client's hostid
48              and vmid strings.
49
50       -Joption
51              Passes option to the JVM, where option is one of the options
52              described on the reference page for the Java application
53              launcher. For example, -J-Xms48m sets the startup memory to 48
54              MB. See java(1).
55

SECURITY

57       The jstatd server can only monitor JVMs for which it has the
58       appropriate native access permissions. Therefore, the jstatd process
59       must be running with the same user credentials as the target JVMs. Some
60       user credentials, such as the root user in UNIX-based systems, have
61       permission to access the instrumentation exported by any JVM on the
62       system. A jstatd process running with such credentials can monitor any
63       JVM on the system, but introduces additional security concerns.
64
65       The jstatd server does not provide any authentication of remote
66       clients. Therefore, running a jstatd server process exposes the
67       instrumentation export by all JVMs for which the jstatd process has
68       access permissions to any user on the network. This exposure might be
69       undesirable in your environment, and therefore, local security policies
70       should be considered before you start the jstatd process, particularly
71       in production environments or on networks that are not secure.
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73       The jstatd server installs an instance of RMISecurityPolicy when no
74       other security manager is installed, and therefore, requires a security
75       policy file to be specified. The policy file must conform to Default
76       Policy Implementation and Policy File Syntax at
77       http://docs.oracle.com/javase/8/docs/technotes/guides/security/PolicyFiles.html
78
79       The following policy file allows the jstatd server to run without any
80       security exceptions. This policy is less liberal than granting all
81       permissions to all code bases, but is more liberal than a policy that
82       grants the minimal permissions to run the jstatd server.
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84       grant codebase "file:${java.home}/../lib/tools.jar" {
85           permission java.security.AllPermission;
86       };
87
88       To use this policy setting, copy the text into a file called
89       jstatd.all.policy and run the jstatd server as follows:
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91       jstatd -J-Djava.security.policy=jstatd.all.policy
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93       For sites with more restrictive security practices, it is possible to
94       use a custom policy file to limit access to specific trusted hosts or
95       networks, though such techniques are subject to IP address spoofing
96       attacks. If your security concerns cannot be addressed with a
97       customized policy file, then the safest action is to not run the jstatd
98       server and use the jstat and jps tools locally.
99

REMOTE INTERFACE

101       The interface exported by the jstatd process is proprietary and
102       guaranteed to change. Users and developers are discouraged from writing
103       to this interface.
104

EXAMPLES

106       The following are examples of the jstatd command. The jstatd scripts
107       automatically start the server in the background
108
109   INTERNAL RMI REGISTRY
110       This example shows hos to start a jstatd session with an internal RMI
111       registry. This example assumes that no other server is bound to the
112       default RMI registry port (port 1099).
113
114       jstatd -J-Djava.security.policy=all.policy
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116
117   EXTERNAL RMI REGISTRY
118       This example starts a jstatd session with a external RMI registry.
119
120       rmiregistry&
121       jstatd -J-Djava.security.policy=all.policy
122
123       This example starts a jstatd session with an external RMI registry
124       server on port 2020.
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126       jrmiregistry 2020&
127       jstatd -J-Djava.security.policy=all.policy -p 2020
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129       This example starts a jstatd session with an external RMI registry on
130       port 2020 that is bound to AlternateJstatdServerName.
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132       rmiregistry 2020&
133       jstatd -J-Djava.security.policy=all.policy -p 2020
134           -n AlternateJstatdServerName
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136
137   STOP THE CREATION OF AN IN-PROCESS RMI REGISTRY
138       This example starts a jstatd session that does not create an RMI
139       registry when one is not found. This example assumes an RMI registry is
140       already running. If an RMI registry is not running, then an error
141       message is displayed.
142
143       jstatd -J-Djava.security.policy=all.policy -nr
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145
146   ENABLE RMI LOGGING
147       This example starts a jstatd session with RMI logging capabilities
148       enabled. This technique is useful as a troubleshooting aid or for
149       monitoring server activities.
150
151       jstatd -J-Djava.security.policy=all.policy
152           -J-Djava.rmi.server.logCalls=true
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SEE ALSO

156       · java(1)
157
158       · jps(1)
159
160       · jstat(1)
161
162       · rmiregistry(1)
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166JDK 8                          21 November 2013                      jstatd(1)
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