How do I check CPU and Memory Usage in Java

Question

I need to check CPU and memory usage for the server in java  anyone know how it could be done

User · Answer

If you are using Tomcat  check out Psi Probe  which lets you monitor internal and external memory consumption as well as a host of other areas

User · Answer

If you are using the Sun JVM  and are interested in the internal memory usage of the application  how much out of the allocated memory your app is using  I prefer to turn on the JVMs built-in garbage collection logging  You simply add -verbose gc to the startup command   From the Sun documentation      The command line argument -verbose gc prints information at every   collection  Note that the format of the -verbose gc output is subject   to change between releases of the J2SE platform  For example  here is   output from a large server application    GC 325407K- gt 83000K 776768K   0 2300771 secs   GC 325816K- gt 83372K 776768K   0 2454258 secs   Full GC 267628K- gt 83769K 776768K   1 8479984 secs        Here we see two minor collections and one major one  The numbers   before and after the arrow  325407K- gt 83000K  in the first line        indicate the combined size of live objects before and after garbage   collection  respectively  After minor collections the count includes   objects that aren t necessarily alive but can t be reclaimed  either   because they are directly alive  or because they are within or   referenced from the tenured generation  The number in parenthesis   776768K   in the first line        is the total available space  not counting the space in the permanent   generation  which is the total heap minus one of the survivor spaces    The minor collection took about a quarter of a second   0 2300771 secs  in the first line     For more info see  http   java sun com docs hotspot gc5 0 gc tuning 5 html

User · Answer

If you use the runtime totalMemory solution that has been posted in many answers here  I ve done that a lot   be sure to force two garbage collections first if you want fairly accurate consistent results   For effiency Java usually allows garbage to fill up all of memory before forcing a GC  and even then it s not usually a complete GC  so your results for runtime freeMemory   always be somewhere between the  real  amount of free memory and 0   The first GC doesn t get everything  it gets most of it   The upswing is that if you just do the freeMemory   call you will get a number that is absolutely useless and varies widely  but if do 2 gc s first it is a very reliable gauge   It also makes the routine MUCH slower  seconds  possibly

User · Answer

If you use the runtime totalMemory solution that has been posted in many answers here  I ve done that a lot   be sure to force two garbage collections first if you want fairly accurate consistent results   For effiency Java usually allows garbage to fill up all of memory before forcing a GC  and even then it s not usually a complete GC  so your results for runtime freeMemory   always be somewhere between the  real  amount of free memory and 0   The first GC doesn t get everything  it gets most of it   The upswing is that if you just do the freeMemory   call you will get a number that is absolutely useless and varies widely  but if do 2 gc s first it is a very reliable gauge   It also makes the routine MUCH slower  seconds  possibly

User · Answer

JConsole is an easy way to monitor a running Java application or you can use a Profiler to get more detailed information on your application  I like using the NetBeans Profiler for this

User · Answer

For Eclipse  you can use TPTP  Test and Performance Tools Platform  for analyse memory usage and etc  more information

User · Answer

Here is some simple code to calculate the current memory usage in megabytes   double currentMemory      double   double  Runtime getRuntime   totalMemory   1024  1024  -   double   double  Runtime getRuntime   freeMemory   1024  1024

User · Answer

The YourKit Java profiler is an excellent commercial solution  You can find further information in the docs on CPU profiling and memory profiling

User · Answer

If you use the runtime totalMemory solution that has been posted in many answers here  I ve done that a lot   be sure to force two garbage collections first if you want fairly accurate consistent results   For effiency Java usually allows garbage to fill up all of memory before forcing a GC  and even then it s not usually a complete GC  so your results for runtime freeMemory   always be somewhere between the  real  amount of free memory and 0   The first GC doesn t get everything  it gets most of it   The upswing is that if you just do the freeMemory   call you will get a number that is absolutely useless and varies widely  but if do 2 gc s first it is a very reliable gauge   It also makes the routine MUCH slower  seconds  possibly

User · Answer

package mkd Utils   import java io File  import java text NumberFormat   public class systemInfo        private Runtime runtime   Runtime getRuntime         public String Info             StringBuilder sb   new StringBuilder            sb append this OsInfo             sb append this MemInfo             sb append this DiskInfo             return sb toString               public String OSname             return System getProperty  os name               public String OSversion             return System getProperty  os version               public String OsArch             return System getProperty  os arch               public long totalMem             return Runtime getRuntime   totalMemory               public long usedMem             return Runtime getRuntime   totalMemory   - Runtime getRuntime   freeMemory               public String MemInfo             NumberFormat format   NumberFormat getInstance            StringBuilder sb   new StringBuilder            long maxMemory   runtime maxMemory            long allocatedMemory   runtime totalMemory            long freeMemory   runtime freeMemory            sb append  Free memory              sb append format format freeMemory   1024            sb append   lt br  gt             sb append  Allocated memory              sb append format format allocatedMemory   1024            sb append   lt br  gt             sb append  Max memory              sb append format format maxMemory   1024            sb append   lt br  gt             sb append  Total free memory              sb append format format  freeMemory    maxMemory - allocatedMemory     1024            sb append   lt br  gt             return sb toString                public String OsInfo             StringBuilder sb   new StringBuilder            sb append  OS              sb append this OSname             sb append   lt br  gt             sb append  Version              sb append this OSversion             sb append   lt br  gt             sb append                sb append this OsArch             sb append   lt br  gt             sb append  Available processors  cores               sb append runtime availableProcessors             sb append   lt br  gt             return sb toString               public String DiskInfo                Get a list of all filesystem roots on this system            File   roots   File listRoots            StringBuilder sb   new StringBuilder                For each filesystem root  print some info            for  File root   roots                sb append  File system root                  sb append root getAbsolutePath                 sb append   lt br  gt                 sb append  Total space  bytes                   sb append root getTotalSpace                 sb append   lt br  gt                 sb append  Free space  bytes                   sb append root getFreeSpace                 sb append   lt br  gt                 sb append  Usable space  bytes                   sb append root getUsableSpace                 sb append   lt br  gt                       return sb toString

User · Answer

If you are looking specifically for memory in JVM   Runtime runtime   Runtime getRuntime     NumberFormat format   NumberFormat getInstance     StringBuilder sb   new StringBuilder    long maxMemory   runtime maxMemory    long allocatedMemory   runtime totalMemory    long freeMemory   runtime freeMemory     sb append  free memory      format format freeMemory   1024      lt br  gt     sb append  allocated memory      format format allocatedMemory   1024      lt br  gt     sb append  max memory      format format maxMemory   1024      lt br  gt     sb append  total free memory      format format  freeMemory    maxMemory - allocatedMemory     1024      lt br  gt       However  these should be taken only as an estimate

User · Answer

Since Java 1 5 the JDK comes with a new tool  JConsole wich can show you the CPU and memory usage of any 1 5 or later JVM  It can do charts of these parameters  export to CSV  show the number of classes loaded  the number of instances  deadlocks  threads etc

User · Answer

If you are using Tomcat  check out Psi Probe  which lets you monitor internal and external memory consumption as well as a host of other areas

User · Answer

JConsole is an easy way to monitor a running Java application or you can use a Profiler to get more detailed information on your application  I like using the NetBeans Profiler for this

User · Answer

Java s Runtime object can report the JVM s memory usage  For CPU consumption you ll have to use an external utility  like Unix s top or Windows Process Manager

User · Answer

I would also add the following way to track CPU Load   import java lang management ManagementFactory  import com sun management OperatingSystemMXBean   double getCpuLoad         OperatingSystemMXBean osBean            com sun management OperatingSystemMXBean  ManagementFactory          getPlatformMXBeans OperatingSystemMXBean class       return osBean getProcessCpuLoad        You can read more here

User · Answer

From here      OperatingSystemMXBean operatingSystemMXBean    OperatingSystemMXBean  ManagementFactory getOperatingSystemMXBean        RuntimeMXBean runtimeMXBean   ManagementFactory getRuntimeMXBean        int availableProcessors   operatingSystemMXBean getAvailableProcessors        long prevUpTime   runtimeMXBean getUptime        long prevProcessCpuTime   operatingSystemMXBean getProcessCpuTime        double cpuUsage      try               Thread sleep 500             catch  Exception ignored           operatingSystemMXBean    OperatingSystemMXBean  ManagementFactory getOperatingSystemMXBean        long upTime   runtimeMXBean getUptime        long processCpuTime   operatingSystemMXBean getProcessCpuTime        long elapsedCpu   processCpuTime - prevProcessCpuTime      long elapsedTime   upTime - prevUpTime       cpuUsage   Math min 99F  elapsedCpu    elapsedTime   10000F   availableProcessors        System out println  Java CPU      cpuUsage

User · Answer

The YourKit Java profiler is an excellent commercial solution  You can find further information in the docs on CPU profiling and memory profiling

User · Answer

package mkd Utils   import java io File  import java text NumberFormat   public class systemInfo        private Runtime runtime   Runtime getRuntime         public String Info             StringBuilder sb   new StringBuilder            sb append this OsInfo             sb append this MemInfo             sb append this DiskInfo             return sb toString               public String OSname             return System getProperty  os name               public String OSversion             return System getProperty  os version               public String OsArch             return System getProperty  os arch               public long totalMem             return Runtime getRuntime   totalMemory               public long usedMem             return Runtime getRuntime   totalMemory   - Runtime getRuntime   freeMemory               public String MemInfo             NumberFormat format   NumberFormat getInstance            StringBuilder sb   new StringBuilder            long maxMemory   runtime maxMemory            long allocatedMemory   runtime totalMemory            long freeMemory   runtime freeMemory            sb append  Free memory              sb append format format freeMemory   1024            sb append   lt br  gt             sb append  Allocated memory              sb append format format allocatedMemory   1024            sb append   lt br  gt             sb append  Max memory              sb append format format maxMemory   1024            sb append   lt br  gt             sb append  Total free memory              sb append format format  freeMemory    maxMemory - allocatedMemory     1024            sb append   lt br  gt             return sb toString                public String OsInfo             StringBuilder sb   new StringBuilder            sb append  OS              sb append this OSname             sb append   lt br  gt             sb append  Version              sb append this OSversion             sb append   lt br  gt             sb append                sb append this OsArch             sb append   lt br  gt             sb append  Available processors  cores               sb append runtime availableProcessors             sb append   lt br  gt             return sb toString               public String DiskInfo                Get a list of all filesystem roots on this system            File   roots   File listRoots            StringBuilder sb   new StringBuilder                For each filesystem root  print some info            for  File root   roots                sb append  File system root                  sb append root getAbsolutePath                 sb append   lt br  gt                 sb append  Total space  bytes                   sb append root getTotalSpace                 sb append   lt br  gt                 sb append  Free space  bytes                   sb append root getFreeSpace                 sb append   lt br  gt                 sb append  Usable space  bytes                   sb append root getUsableSpace                 sb append   lt br  gt                       return sb toString

User · Answer

If you are using the Sun JVM  and are interested in the internal memory usage of the application  how much out of the allocated memory your app is using  I prefer to turn on the JVMs built-in garbage collection logging  You simply add -verbose gc to the startup command   From the Sun documentation      The command line argument -verbose gc prints information at every   collection  Note that the format of the -verbose gc output is subject   to change between releases of the J2SE platform  For example  here is   output from a large server application    GC 325407K- gt 83000K 776768K   0 2300771 secs   GC 325816K- gt 83372K 776768K   0 2454258 secs   Full GC 267628K- gt 83769K 776768K   1 8479984 secs        Here we see two minor collections and one major one  The numbers   before and after the arrow  325407K- gt 83000K  in the first line        indicate the combined size of live objects before and after garbage   collection  respectively  After minor collections the count includes   objects that aren t necessarily alive but can t be reclaimed  either   because they are directly alive  or because they are within or   referenced from the tenured generation  The number in parenthesis   776768K   in the first line        is the total available space  not counting the space in the permanent   generation  which is the total heap minus one of the survivor spaces    The minor collection took about a quarter of a second   0 2300771 secs  in the first line     For more info see  http   java sun com docs hotspot gc5 0 gc tuning 5 html

User · Answer

Since Java 1 5 the JDK comes with a new tool  JConsole wich can show you the CPU and memory usage of any 1 5 or later JVM  It can do charts of these parameters  export to CSV  show the number of classes loaded  the number of instances  deadlocks  threads etc

User · Answer

If you use the runtime totalMemory solution that has been posted in many answers here  I ve done that a lot   be sure to force two garbage collections first if you want fairly accurate consistent results   For effiency Java usually allows garbage to fill up all of memory before forcing a GC  and even then it s not usually a complete GC  so your results for runtime freeMemory   always be somewhere between the  real  amount of free memory and 0   The first GC doesn t get everything  it gets most of it   The upswing is that if you just do the freeMemory   call you will get a number that is absolutely useless and varies widely  but if do 2 gc s first it is a very reliable gauge   It also makes the routine MUCH slower  seconds  possibly

User · Answer

For memory usage  the following will work   long total   Runtime getRuntime   totalMemory    long used    Runtime getRuntime   totalMemory   - Runtime getRuntime   freeMemory      For CPU usage  you ll need to use an external application to measure it

User · Answer

Here is some simple code to calculate the current memory usage in megabytes   double currentMemory      double   double  Runtime getRuntime   totalMemory   1024  1024  -   double   double  Runtime getRuntime   freeMemory   1024  1024

User · Answer

If you are using Tomcat  check out Psi Probe  which lets you monitor internal and external memory consumption as well as a host of other areas

User · Answer

If you are looking specifically for memory in JVM   Runtime runtime   Runtime getRuntime     NumberFormat format   NumberFormat getInstance     StringBuilder sb   new StringBuilder    long maxMemory   runtime maxMemory    long allocatedMemory   runtime totalMemory    long freeMemory   runtime freeMemory     sb append  free memory      format format freeMemory   1024      lt br  gt     sb append  allocated memory      format format allocatedMemory   1024      lt br  gt     sb append  max memory      format format maxMemory   1024      lt br  gt     sb append  total free memory      format format  freeMemory    maxMemory - allocatedMemory     1024      lt br  gt       However  these should be taken only as an estimate

User · Answer

Java s Runtime object can report the JVM s memory usage  For CPU consumption you ll have to use an external utility  like Unix s top or Windows Process Manager

User · Answer

JMX  The MXBeans  ThreadMXBean  etc  provided will give you Memory and CPU usages   OperatingSystemMXBean operatingSystemMXBean    OperatingSystemMXBean  ManagementFactory getOperatingSystemMXBean    operatingSystemMXBean getSystemCpuLoad

User · Answer

JMX  The MXBeans  ThreadMXBean  etc  provided will give you Memory and CPU usages   OperatingSystemMXBean operatingSystemMXBean    OperatingSystemMXBean  ManagementFactory getOperatingSystemMXBean    operatingSystemMXBean getSystemCpuLoad

User · Answer

For memory usage  the following will work   long total   Runtime getRuntime   totalMemory    long used    Runtime getRuntime   totalMemory   - Runtime getRuntime   freeMemory      For CPU usage  you ll need to use an external application to measure it

User · Answer

The YourKit Java profiler is an excellent commercial solution  You can find further information in the docs on CPU profiling and memory profiling

User · Answer

If you are using the Sun JVM  and are interested in the internal memory usage of the application  how much out of the allocated memory your app is using  I prefer to turn on the JVMs built-in garbage collection logging  You simply add -verbose gc to the startup command   From the Sun documentation      The command line argument -verbose gc prints information at every   collection  Note that the format of the -verbose gc output is subject   to change between releases of the J2SE platform  For example  here is   output from a large server application    GC 325407K- gt 83000K 776768K   0 2300771 secs   GC 325816K- gt 83372K 776768K   0 2454258 secs   Full GC 267628K- gt 83769K 776768K   1 8479984 secs        Here we see two minor collections and one major one  The numbers   before and after the arrow  325407K- gt 83000K  in the first line        indicate the combined size of live objects before and after garbage   collection  respectively  After minor collections the count includes   objects that aren t necessarily alive but can t be reclaimed  either   because they are directly alive  or because they are within or   referenced from the tenured generation  The number in parenthesis   776768K   in the first line        is the total available space  not counting the space in the permanent   generation  which is the total heap minus one of the survivor spaces    The minor collection took about a quarter of a second   0 2300771 secs  in the first line     For more info see  http   java sun com docs hotspot gc5 0 gc tuning 5 html

User · Answer

JConsole is an easy way to monitor a running Java application or you can use a Profiler to get more detailed information on your application  I like using the NetBeans Profiler for this

User · Answer

JConsole is an easy way to monitor a running Java application or you can use a Profiler to get more detailed information on your application  I like using the NetBeans Profiler for this

User · Answer

The YourKit Java profiler is an excellent commercial solution  You can find further information in the docs on CPU profiling and memory profiling

User · Answer

I would also add the following way to track CPU Load   import java lang management ManagementFactory  import com sun management OperatingSystemMXBean   double getCpuLoad         OperatingSystemMXBean osBean            com sun management OperatingSystemMXBean  ManagementFactory          getPlatformMXBeans OperatingSystemMXBean class       return osBean getProcessCpuLoad        You can read more here

User · Answer

Since Java 1 5 the JDK comes with a new tool  JConsole wich can show you the CPU and memory usage of any 1 5 or later JVM  It can do charts of these parameters  export to CSV  show the number of classes loaded  the number of instances  deadlocks  threads etc

User · Answer

Since Java 1 5 the JDK comes with a new tool  JConsole wich can show you the CPU and memory usage of any 1 5 or later JVM  It can do charts of these parameters  export to CSV  show the number of classes loaded  the number of instances  deadlocks  threads etc

User · Answer

From here      OperatingSystemMXBean operatingSystemMXBean    OperatingSystemMXBean  ManagementFactory getOperatingSystemMXBean        RuntimeMXBean runtimeMXBean   ManagementFactory getRuntimeMXBean        int availableProcessors   operatingSystemMXBean getAvailableProcessors        long prevUpTime   runtimeMXBean getUptime        long prevProcessCpuTime   operatingSystemMXBean getProcessCpuTime        double cpuUsage      try               Thread sleep 500             catch  Exception ignored           operatingSystemMXBean    OperatingSystemMXBean  ManagementFactory getOperatingSystemMXBean        long upTime   runtimeMXBean getUptime        long processCpuTime   operatingSystemMXBean getProcessCpuTime        long elapsedCpu   processCpuTime - prevProcessCpuTime      long elapsedTime   upTime - prevUpTime       cpuUsage   Math min 99F  elapsedCpu    elapsedTime   10000F   availableProcessors        System out println  Java CPU      cpuUsage

User · Answer

Java s Runtime object can report the JVM s memory usage  For CPU consumption you ll have to use an external utility  like Unix s top or Windows Process Manager

User · Answer

JMX  The MXBeans  ThreadMXBean  etc  provided will give you Memory and CPU usages   OperatingSystemMXBean operatingSystemMXBean    OperatingSystemMXBean  ManagementFactory getOperatingSystemMXBean    operatingSystemMXBean getSystemCpuLoad

User · Answer

Java s Runtime object can report the JVM s memory usage  For CPU consumption you ll have to use an external utility  like Unix s top or Windows Process Manager

User · Answer

If you are using Tomcat  check out Psi Probe  which lets you monitor internal and external memory consumption as well as a host of other areas

User · Answer

JMX  The MXBeans  ThreadMXBean  etc  provided will give you Memory and CPU usages   OperatingSystemMXBean operatingSystemMXBean    OperatingSystemMXBean  ManagementFactory getOperatingSystemMXBean    operatingSystemMXBean getSystemCpuLoad

User · Answer

If you are looking specifically for memory in JVM   Runtime runtime   Runtime getRuntime     NumberFormat format   NumberFormat getInstance     StringBuilder sb   new StringBuilder    long maxMemory   runtime maxMemory    long allocatedMemory   runtime totalMemory    long freeMemory   runtime freeMemory     sb append  free memory      format format freeMemory   1024      lt br  gt     sb append  allocated memory      format format allocatedMemory   1024      lt br  gt     sb append  max memory      format format maxMemory   1024      lt br  gt     sb append  total free memory      format format  freeMemory    maxMemory - allocatedMemory     1024      lt br  gt       However  these should be taken only as an estimate

User · Answer

If you are using the Sun JVM  and are interested in the internal memory usage of the application  how much out of the allocated memory your app is using  I prefer to turn on the JVMs built-in garbage collection logging  You simply add -verbose gc to the startup command   From the Sun documentation      The command line argument -verbose gc prints information at every   collection  Note that the format of the -verbose gc output is subject   to change between releases of the J2SE platform  For example  here is   output from a large server application    GC 325407K- gt 83000K 776768K   0 2300771 secs   GC 325816K- gt 83372K 776768K   0 2454258 secs   Full GC 267628K- gt 83769K 776768K   1 8479984 secs        Here we see two minor collections and one major one  The numbers   before and after the arrow  325407K- gt 83000K  in the first line        indicate the combined size of live objects before and after garbage   collection  respectively  After minor collections the count includes   objects that aren t necessarily alive but can t be reclaimed  either   because they are directly alive  or because they are within or   referenced from the tenured generation  The number in parenthesis   776768K   in the first line        is the total available space  not counting the space in the permanent   generation  which is the total heap minus one of the survivor spaces    The minor collection took about a quarter of a second   0 2300771 secs  in the first line     For more info see  http   java sun com docs hotspot gc5 0 gc tuning 5 html

User · Answer

If you are looking specifically for memory in JVM   Runtime runtime   Runtime getRuntime     NumberFormat format   NumberFormat getInstance     StringBuilder sb   new StringBuilder    long maxMemory   runtime maxMemory    long allocatedMemory   runtime totalMemory    long freeMemory   runtime freeMemory     sb append  free memory      format format freeMemory   1024      lt br  gt     sb append  allocated memory      format format allocatedMemory   1024      lt br  gt     sb append  max memory      format format maxMemory   1024      lt br  gt     sb append  total free memory      format format  freeMemory    maxMemory - allocatedMemory     1024      lt br  gt       However  these should be taken only as an estimate

User · Answer

For memory usage  the following will work   long total   Runtime getRuntime   totalMemory    long used    Runtime getRuntime   totalMemory   - Runtime getRuntime   freeMemory      For CPU usage  you ll need to use an external application to measure it

User · Answer

For Eclipse  you can use TPTP  Test and Performance Tools Platform  for analyse memory usage and etc  more information

User · Answer

For memory usage  the following will work   long total   Runtime getRuntime   totalMemory    long used    Runtime getRuntime   totalMemory   - Runtime getRuntime   freeMemory      For CPU usage  you ll need to use an external application to measure it

[java] How do I check CPU and Memory Usage in Java?

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