1 .\" Copyright (c) 1994, 2019, Oracle and/or its affiliates. All rights reserved. 2 .\" DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 3 .\" 4 .\" This code is free software; you can redistribute it and/or modify it 5 .\" under the terms of the GNU General Public License version 2 only, as 6 .\" published by the Free Software Foundation. 7 .\" 8 .\" This code is distributed in the hope that it will be useful, but WITHOUT 9 .\" ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 .\" FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 11 .\" version 2 for more details (a copy is included in the LICENSE file that 12 .\" accompanied this code). 13 .\" 14 .\" You should have received a copy of the GNU General Public License version 15 .\" 2 along with this work; if not, write to the Free Software Foundation, 16 .\" Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 17 .\" 18 .\" Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 19 .\" or visit www.oracle.com if you need additional information or have any 20 .\" questions. 21 .\" 22 .\" Automatically generated by Pandoc 2.3.1 23 .\" 24 .TH "JSTATD" "1" "2018" "JDK 13" "JDK Commands" 25 .hy 26 .SH NAME 27 .PP 28 jstatd \- monitor the creation and termination of instrumented Java 29 HotSpot VMs 30 .SH SYNOPSIS 31 .PP 32 \f[B]Note:\f[R] This command is experimental\ and unsupported. 33 .PP 34 \f[CB]jstatd\f[R] [\f[I]options\f[R]] 35 .TP 36 .B \f[I]options\f[R] 37 This represents the \f[CB]jstatd\f[R] command\-line options. 38 See \f[B]Options for the jstatd Command\f[R]. 39 .RS 40 .RE 41 .SH DESCRIPTION 42 .PP 43 The \f[CB]jstatd\f[R] command is an RMI server application that monitors 44 for the creation and termination of instrumented Java HotSpot VMs and 45 provides an interface to enable remote monitoring tools, \f[CB]jstat\f[R] 46 and \f[CB]jps\f[R], to attach to JVMs that are running on the local host 47 and collect information about the JVM process. 48 .PP 49 The \f[CB]jstatd\f[R] server requires an RMI registry on the local host. 50 The \f[CB]jstatd\f[R] server attempts to attach to the RMI registry on the 51 default port, or on the port you specify with the \f[CB]\-p\f[R] 52 \f[CB]port\f[R] option. 53 If an RMI registry is not found, then one is created within the 54 \f[CB]jstatd\f[R] application that\[aq]s bound to the port that\[aq]s 55 indicated by the \f[CB]\-p\f[R] \f[CB]port\f[R] option or to the default RMI 56 registry port when the \f[CB]\-p\f[R] \f[CB]port\f[R] option is omitted. 57 You can stop the creation of an internal RMI registry by specifying the 58 \f[CB]\-nr\f[R] option. 59 .SH OPTIONS FOR THE JSTATD COMMAND 60 .TP 61 .B \f[CB]\-nr\f[R] 62 This option does not attempt to create an internal RMI registry within 63 the \f[CB]jstatd\f[R] process when an existing RMI registry isn\[aq]t 64 found. 65 .RS 66 .RE 67 .TP 68 .B \f[CB]\-p\f[R] \f[I]port\f[R] 69 This option sets the port number where the RMI registry is expected to 70 be found, or when not found, created if the \f[CB]\-nr\f[R] option 71 isn\[aq]t specified. 72 .RS 73 .RE 74 .TP 75 .B \f[CB]\-n\f[R] \f[I]rminame\f[R] 76 This option sets the name to which the remote RMI object is bound in the 77 RMI registry. 78 The default name is \f[CB]JStatRemoteHost\f[R]. 79 If multiple \f[CB]jstatd\f[R] servers are started on the same host, then 80 the name of the exported RMI object for each server can be made unique 81 by specifying this option. 82 However, doing so requires that the unique server name be included in 83 the monitoring client\[aq]s \f[CB]hostid\f[R] and \f[CB]vmid\f[R] strings. 84 .RS 85 .RE 86 .TP 87 .B \f[CB]\-J\f[R]\f[I]option\f[R] 88 This option passes a Java \f[CB]option\f[R] to the JVM, where the option 89 is one of those described on the reference page for the Java application 90 launcher. 91 For example, \f[CB]\-J\-Xms48m\f[R] sets the startup memory to 48 MB. 92 See \f[B]java\f[R]. 93 .RS 94 .RE 95 .SH SECURITY 96 .PP 97 The \f[CB]jstatd\f[R] server can monitor only JVMs for which it has the 98 appropriate native access permissions. 99 Therefore, the \f[CB]jstatd\f[R] process must be running with the same 100 user credentials as the target JVMs. 101 Some user credentials, such as the root user in Oracle Solaris, Linux, 102 and OS X operating systems, have permission to access the 103 instrumentation exported by any JVM on the system. 104 A \f[CB]jstatd\f[R] process running with such credentials can monitor any 105 JVM on the system, but introduces additional security concerns. 106 .PP 107 The \f[CB]jstatd\f[R] server doesn\[aq]t provide any authentication of 108 remote clients. 109 Therefore, running a \f[CB]jstatd\f[R] server process exposes the 110 instrumentation export by all JVMs for which the \f[CB]jstatd\f[R] process 111 has access permissions to any user on the network. 112 This exposure might be undesirable in your environment, and therefore, 113 local security policies should be considered before you start the 114 \f[CB]jstatd\f[R] process, particularly in production environments or on 115 networks that aren\[aq]t secure. 116 .PP 117 The \f[CB]jstatd\f[R] server installs an instance of 118 \f[CB]RMISecurityPolicy\f[R] when no other security manager is installed, 119 and therefore, requires a security policy file to be specified. 120 The policy file must conform to Default Policy Implementation and Policy 121 File Syntax. 122 .PP 123 If your security concerns can\[aq]t be addressed with a customized 124 policy file, then the safest action is to not run the \f[CB]jstatd\f[R] 125 server and use the \f[CB]jstat\f[R] and \f[CB]jps\f[R] tools locally. 126 However, when using \f[CB]jps\f[R] to get a list of instrumented JVMs, the 127 list will not include any JVMs running in docker containers. 128 .SH REMOTE INTERFACE 129 .PP 130 The interface exported by the \f[CB]jstatd\f[R] process is proprietary and 131 guaranteed to change. 132 Users and developers are discouraged from writing to this interface. 133 .SH EXAMPLES 134 .PP 135 The following are examples of the \f[CB]jstatd\f[R] command. 136 The \f[CB]jstatd\f[R] scripts automatically start the server in the 137 background. 138 .SH INTERNAL RMI REGISTRY 139 .PP 140 This example shows how to start a \f[CB]jstatd\f[R] session with an 141 internal RMI registry. 142 This example assumes that no other server is bound to the default RMI 143 registry port (port \f[CB]1099\f[R]). 144 .RS 145 .PP 146 \f[CB]jstatd\ \-J\-Djava.security.policy=all.policy\f[R] 147 .RE 148 .SH EXTERNAL RMI REGISTRY 149 .PP 150 This example starts a \f[CB]jstatd\f[R] session with an external RMI 151 registry. 152 .IP 153 .nf 154 \f[CB] 155 rmiregistry& 156 jstatd\ \-J\-Djava.security.policy=all.policy 157 \f[R] 158 .fi 159 .PP 160 This example starts a \f[CB]jstatd\f[R] session with an external RMI 161 registry server on port \f[CB]2020\f[R]. 162 .IP 163 .nf 164 \f[CB] 165 jrmiregistry\ 2020& 166 jstatd\ \-J\-Djava.security.policy=all.policy\ \-p\ 2020 167 \f[R] 168 .fi 169 .PP 170 This example starts a \f[CB]jstatd\f[R] session with an external RMI 171 registry on port 2020 that\[aq]s bound to 172 \f[CB]AlternateJstatdServerName\f[R]. 173 .IP 174 .nf 175 \f[CB] 176 rmiregistry\ 2020& 177 jstatd\ \-J\-Djava.security.policy=all.policy\ \-p\ 2020\ \-n\ AlternateJstatdServerName 178 \f[R] 179 .fi 180 .SH STOP THE CREATION OF AN IN\-PROCESS RMI REGISTRY 181 .PP 182 This example starts a \f[CB]jstatd\f[R] session that doesn\[aq]t create an 183 RMI registry when one isn\[aq]t found. 184 This example assumes an RMI registry is already running. 185 If an RMI registry isn\[aq]t running, then an error message is 186 displayed. 187 .RS 188 .PP 189 \f[CB]jstatd\ \-J\-Djava.security.policy=all.policy\ \-nr\f[R] 190 .RE 191 .SH ENABLE RMI LOGGING 192 .PP 193 This example starts a \f[CB]jstatd\f[R] session with RMI logging 194 capabilities enabled. 195 This technique is useful as a troubleshooting aid or for monitoring 196 server activities. 197 .RS 198 .PP 199 \f[CB]jstatd\ \-J\-Djava.security.policy=all.policy\ \-J\-Djava.rmi.server.logCalls=true\f[R] 200 .RE