The use of ZVision should be taken under careful consideration since access to sensitive performance data should be restricted following company policy and security recommendations.

Enables ZVision and allows the ZVision server to listen on the specified port of the host where the ZVM is running. Valid options include:

• off – disables ZVision (default).
• <port> – port number for ZVision to use on the host. The value should be greater than or equal to 1025 and less than or equal to 65535.
• any – ZVision uses any free port. This setting is useful when starting multiple instances of ZVision for multiple VMs.

Supply a port number or set this option to any to enable ZVision.

The ARTA (Azul Run Time Analysis) port provides internal API communication between ZVision and ZVM.

Set the number of historical PGC cycle reports to save for display in ZVision (default =50).

Display a list of supported command line options

Specify the port number port number that browsers listen to the ZVision server

Specify the network interface that the ZVM accepts HTTP connections.

Specify the timeout interval (in seconds) when communicating with the ZVM.

Specify the debug logging level: debug, info, warning, error, or critical

Displays information for all process settings for the ZVM.

Displays information for all environmental variables set by the shell that launched the ZVM front end.

Displays information for all of the HotSpot flags that the ZVM uses.

Displays information about running applications.

Displays configuration to enable GC logging, control level of detail logged, and destination of the output.

This feature is not supported at this time.

This feature is not supported at this time.

Enables or disables user access to restricted ZVision features.

Displays all threads with links to detailed information for each thread.

Lists all threads with information whether each one is executing or blocked.

Lists detected deadlock cycles.

Displays statistics for each monitor (sorted by total time held).

Provides additional information about the selected monitor in contention.

Displays information that shows how percentage of processor core time used for an interval of recorded time.

Lists the time it takes to complete logical tasks.

This feature is not supported at this time.

Displays a summary of total memory usage and Contingency memory usage.

Displays a cumulative summary of recent GC cycle history.

Displays a detailed summary of recent GC cycle history (one row per collection).

Displays information about object, instance, method, or class.

Displays information on allocated objects by object type.

Displays information on class instances.

Displays a current list of classes in the old generation heap and their rate of memory growth.

Displays the status of Server and Client compiler tasks.

The ZVM version.

The list of classes and command line options used to launch a Java application.

The Java Home path.

The path to the class.

The path to the boot class.

The directories for extensions.

The directories for classes implementing newer versions of endorsed standards.

The native library path.

The boot library path.

The version of the instrumentation in the ZVM that provides data to the ZVision server.

The limit in bytes for open file descriptors for the ZVM front end.

Name of the environment variable.

The type of flag. Possible values are:

• Boolean – the flag requires a Boolean value of true (+) or false (-).
• Integer or Unsigned Integer – the flag requires an integer value.
• String – the flag requires a string.

The name of the flag.

The value configured for the flag.

Displays the number of Java classes loaded in the ZVM.

Disables GC logging for this ZVM instance. This is the default setting.

Enables GC logging with summarized output. Output is equivalent to using the command line option -XX:+PrintGC.

Enables GC logging with detailed output. Output is equivalent to using the command line option -XX:+PrintGCDetails.

Enabling user access to any of these features may interfere with the ZVM, cause system delays, or expose sensitive information.

Enables user access to Azul Customer Support Options. Use at your risk, as some of these diagnostic features can interfere with the proper functioning of the ZVM, or cause the system to crash.

Enables users to browse a class instance. Turning this feature on could expose sensitive data within the object.

Enables users to browse the static class data. Turning this feature on could expose sensitive data within the object.

Enables users to browse a class method. Turning this feature on could expose sensitive data within the object.

Enables users to view the Environment Variables. Turning this feature on could expose sensitive data.

Enables users to use the Stack Trace window. Turning this feature on could expose sensitive data.

Enables users to view metaticks. Turning this feature on could interfere with the proper functioning of the VM and cause the system to crash. This tab should ONLY be enabled if advised by Azul Support.

Enables users to view the Polling Opportunities entries. Turning this feature on could interfere with the proper functioning of the VM and cause the system to crash. This tab should ONLY be enabled if advised by Azul Support.

Lists the name of the thread as assigned by the application.

The most common states for threads are:

• running – the thread is executing on a processor core.
• I/O wait – the thread is waiting for socket or file I/O.
• waiting on monitor – the thread is blocked in java.lang.Object.wait() awaiting notification.
• low memory detection –
• acquiring monitor – the thread is waiting to acquire a synchronization monitor.
• acquiring and releasing monitor – the thread a requires and releases a synchronization monitor. This typically happens when the critical section of the monitor is extremely small.
• sleeping – the thread executed java.lang.Thread.sleep().
• Other states, such as idle, semaphore wait, waiting on ZVM monitor Threads_lock, or Waiting on Monitor SLT lock indicate threads that are internal to the ZVM. These states are not normally useful for analysis of application performance. Also, during start up, compiler threads may be running. The time (in seconds) that the thread has spent since entering the state is provided in parenthesis after the waiting state indicators.

The name of the monitor.

• Total – the time, in milliseconds, for acquires to occur for a given internal or Java-level monitor (not tracked for lightly contended “thin” monitors).
• Max (ms) – the maximum time, in milliseconds, to perform an acquire.

• Count – the number of blocking acquires.

Method names in the tick profiler are compiled methods and are no longer being interpreted. All time spent by methods being interpreted is summed as one entry named “Interpreter.”

Click Pause The Tick Collection to stop refreshing the list of ticks. This is useful when you need to locate a specific item in a rapidly changing list. Click Resume The Tick Collection and refresh the screen to continue updating the list of ticks.

Clears the existing list of ticks and restarts tick collection.

Filters the list of ticks to list only those values that are greater than or equal to the set cutoff value. Enter value. Click Submit.

At the bottom of the list of ticks, it lists the percentage and number of ticks that are not included in the displayed list as defined by the Cutoff percent value and Threads value.

Display the ticks for only the threads listed in this field. Enter value. Click Submit.

The three radio buttons filter the tick data by a tag assigned to it. Whenever a thread is running, it has a current tag assigned to it. That value can change at any time, as the thread does different things. For instance, if you have a thread that is a garbage collection thread, it's tag might be "garbage collection" most of the time, but when that thread was running some specific subtask of GC, it might say GC marking phase. This feature allows collates and displays the data from the aspect of the tag value instead of the method name.

The options are:

• None – don't filter the list by tags.
• JVM -- group all the JVM compiler ticks into one entry, so that everything is lumped together. Useful if you are trying to get a sense of what overhead the compiler is having.
• All - only display ticks by tag type for all threads. Instead of showing ticks entries by their method name, group and display them by their tag type.

To apply tag filter:

Click a radio button. Click Submit.

The percentage of CPU resources (% of the total number of ticks collected during the collection period) the function used during the time interval.

The number of program counters (“ticks”) collected in the time interval. This includes:

• Timer ticks – collect for each tick, the thread ID, CPU, stack trace and last eight calling functions when the tick occurs. The time reported, in milliseconds, is thread time, not clock time.
• Time to safe point ticks – collect the time required to complete a save point process.

A description of the function being counted. The following are definitions for specific functions:

• VM_GC Task – the garbage collector for the ZVM.
• ARTA_Performance_Monitor – the function that collects and displays ZVision data.
• VM_C2 Compiler – the ZVM JIT compiler compiling methods indicating that an application is still warming up .
• generate_monitor enter – the amount of time spent busy-waiting to acquire monitors.

Click Pause The Tick Collection to stop refreshing the list of ticks. This is useful when you need to locate a specific item in a rapidly changing list. Click Resume The Tick Collection and refresh the screen to continue updating the list of ticks.

Clears the existing list of ticks and restarts tick collection.

• Entries Displayed – number of entries displayed on a given page.
• Tick Start – a search field which determines the earliest tick that is included in the display, based on the elapsed tick counter.
• Tick End – a search field which determines the latest tick that is
• included in the display, based on the elapsed tick counter.

These items are all search criteria for metaticks. The five fields in this row can all use comma separated lists as a search criteria. That is, you can search for more than one term simultaneously, by listing those terms with commas separating them. For example, CPU field could contain "2,5,9", which would list all metaticks that came from CPU 2, 5 or 9.

• MetaTick # – value that can be used for searches. The values are preassigned by Azul.
• User Info # – value assigned dynamically by the application that can be searched on.
• Tag # – The current Virtual Machine Process Tag of the thread when the metatick occurred. This is a pre-defined value we assign to a thread that can be changed dynamically, to indicate what kind of work the thread is doing. The values are preassigned by Azul.
• CPU # – the CPU that the thread was executing on when the metatick occurred.
• Thread # – thread ID for Azul internal use.

List of actual metatick data. See below listed field descriptions.

• Line item – last 100 meta ticks recorded.
• Tick Counter – elapsed ticks since startup.
• Thread ID – thread ID for Azul internal use.
• CPU – CPU that the thread was executing on when the metatick occurred.
• MetaTick Type – value for Azul internal use. Value indicates the tag value at the time the tick occurred.
• MetaTick Type # – string translation of the stored bit value to the metatick type.
• Tag Name – string human readable translation of the tag number.
• Tag # – the VM Tag currently assigned when the metatick occurred
• Stack Frame Address – address of the stack frame at the time the tick occurred.

The amount of memory currently used by the ZVM.

The amount of memory allocated for use by the ZVM.

The maximum amount of memory requested for use by the ZVM (-Xmx).

Shows allocated, balance, Reserved, and Contingency memory usage for the ZVM

Shows allocated, balance, Reserved, and Contingency memory usage for the Java heap.

• Category – element being measured
• Statistic – aspect of the element being measured
• Mean – statistical calculation of collected values
• Stddev – standard deviation calculated for collected values
• Min – minimum value in collected sample
• Max – maximum value in collected sample

• Interval (sec) – elapsed time between successive GC cycle starts.
• Pause ratio – ratio of time application spent in safepoint pauses during the cycle to cycle interval time

• Peak used (MB) – the peak size of the Java heap recorded during the GC cycle

These values are used for internal Zing diagnostic purposes only.

• New used (MB) – the amount of memory used by all young objects not known to be dead during the GC cycle.

• Old used (MB) – the amount of memory used by all old objects not known to be dead during the GC cycle.
• Perm used (MB) – the amount of memory used by all permanent objects not known to be dead during the GC cycle.
• Live (MB) – the live memory in the generation(s) being collected.
• Fragmentation (MB) – the fragmentation in the generation(s) being collected.

• Found (MB) – the garbage found in the generation(s) being collected.
• Collected (MB) – the garbage freed in the generation(s) being collected.
• Sideband limited (MB) – used for internal Zing diagnostics purposes only.

These values are used for internal Zing diagnostic purposes only.

• Pause 1 duration (ms) – the duration time of the pause 1 safepoint.
• Pause 2 duration (ms) – the duration of the pause 2 safepoint
• Pause 3 duration (ms) – the duration of the pause 3 safepoint
• Pause 4 duration (ms) – the total duration of all pause 4 safepoints for this GC cycle.

• Duration (sec.) – the elapsed time from the end of the last GC cycle to the start of this GC cycle.
• Allocation rate (MB/s) – the object allocation rate in the generation being collected in the period between the last GC cycle to the start of this GC cycle.
• Perm allocation rate (MB/s) – the object allocation rate in the permanent generation during this GC cycle.

• Duration (sec.) – the GC cycle elapsed time; the duration of time from the beginning to the end of this GC cycle.
• Allocation rate (MB/s) – the object allocation rate in the generation being collected during this GC cycle.
• Perm allocation rate (MB/s) – the object allocation rate in the permanent generation during this GC cycle.

Indicates GC cycle, as follows:

• Old – old generation cycle
• New – new generation cycle
• NTO – new generation cycle that immediately precedes an Old Gen cycle

For each New or Old Gen cycle, the number of that collection in the sequence of all collections of that type (New or Old Gen).

• p – indicates if allocation from pause memory is enabled
• g – indicates if allocation from Contingency memory is enabled.

• Max – maximum amount of heap memory guaranteed to the application. This is generally set by Xmx option.

• Peak – the peak size of the Java heap recorded during the GC cycle.
• Used – the amount of memory used by all objects not known to be dead during the GC cycle.

These values are used for internal Zing diagnostic purposes only.

• New – the amount of memory used by all young objects not known to be dead during the GC cycle.

• Old – the amount of memory used by all old objects not known to be dead during the GC cycle.
• Perm – the amount of memory used by all permanent objects not known to be dead during the GC cycle.
• Live – the live memory in the generation(s) being collected.
• Frag – the fragmentation in the generation(s) being collected.

• Found – the garbage found in the generation(s) being collected.
• Freed – the garbage freed in the generation(s) being collected.
• Sideband limited – used for internal Zing diagnostics purposes only.

These values are used for internal Zing diagnostic purposes only.

• Dur (sec.) – the elapsed time from the end of the last GC cycle to the start of this GC cycle.
• Alloc rate (MB/s) – the object allocation rate in the generation being collected in the period between the last GC cycle to the start of this GC cycle.
• Perm alloc rate (MB/s) – the object allocation rate in the permanent generation during this GC cycle.

• Dur (sec.) – the GC cycle elapsed time; the duration of time from the beginning to the end of this GC cycle.
• Alloc rate (MB/s) – the object allocation rate in the generation being collected during this GC cycle.
• Perm alloc rate (MB/s) – the object allocation rate in the permanent generation during this GC cycle.

• # – the total count of Java threads in the ZVM.

If applicable, list of class properties associated with the selected object. Includes values for the listed properties.

If applicable, list of static information associated with the selected object. This includes descriptive information:

• Access
• Name
• Type
• Value

If applicable, list of methods associated with the selected object.

Total number of old generation live objects.

Name of classes whose objects reside in old generation memory. Click the plus (+) to see referring classes.

The number of objects of this class that are alive in the old generation heap.

The total amount of memory used by objects of this class.

The average amount of memory used by objects of this class.

Options in increments ranging: 1 – 45 mins, 1-18 hrs, 1-7 days

Selected time interval by the user. See options in Interval.

Time interval starting from the last GC cycle that most closely matches the selected interval.

For example, if GC occurred at 10 minutes, 15 minutes, 20 minutes, and 45 minutes from the start of the VM, and the selected interval is 10, then the data from the GC at 20 minutes (interval-start) and 45 minutes (interval-end) are used for calculating the type velocity.

The starting time and ending time of the best available match interval. Time is not clock time. It is time from start of VM.

Amount of time passed since the start of the VM.

Name of classes whose objects reside in old generation memory.

The number of objects of this class that are alive at interval-end time.

The total amount of memory used by objects of this class that are alive at interval-end time.

The number of objects of this class that are alive at interval-start time.

The total amount of memory used by objects of this class that are alive at interval-start time.

The difference between the number of objects of this class that are alive between interval-start and interval-end time.

The difference between the memory used by objects of this class between interval-start and interval-end time.

Status of threads being compiled.