Members

You can use the Members menu item to monitor each member in a cluster and perform management operations on any member such as running garbage collection (GC), taking a thread dump, and shutting it down.

Member Grid View

Table 1. Member statistics overview
Field Description

Member

The IP address and port of the member.

Additional Info

Displays an info icon if the member is a CP member or a warning icon if the member’s runtime or hardware setup does not conform to our production recommendations. Hover over the icon to see the tooltip. For a list of production recommendations, see Production Checklist in the Platform documentation. To monitor and manage the CP subsystem, see CP Subsystem.

Scripting

Whether scripting is enabled. See Scripting

Streaming

Whether the Jet engine is enabled. See Configuring the Jet Engine in the Platform documentation.

Slow Operations

Whether the member has detected slow operations. See Slow Operations on this page.

Hazelcast Version

Version of the member codebase that the member is running.

Owned Partitions

Number of partitions that are owned by the member.

OS Total Physical Memory

Total amount of physical memory on the member.

OS Committed Virtual Memory

Amount of virtual memory that is guaranteed to be available to the running member.

OS Free Physical Memory

Amount of free physical memory on the member.

OS CPU Load

Recent CPU usage for the whole system represented as a percentage value. 0% means that all CPUs were idle during the recent period of time observed, while 100% means that all CPUs were actively running during the recent period being observed.

OS Max File Desc

Maximum number of file descriptors. File descriptor is an integer number that uniquely represents an opened file in the operating system.

OS Open File Desc

Number of open file descriptors.

Intel® Optane™ DC

Whether the cluster uses Intel® Optane™ DC memory. See Store Persistence Data on Intel® Optane™ DC Persistent Memory in the Platform documentation.

Filtering Members

To filter the displayed members, use the Search bar in the right-hand corner.

To sort the table, click on the column headers.

Viewing Details about a Member

To see more details about a particular member, click on the member’s row in the table.

Monitoring Members

Actions

On each member, you can trigger the following actions:

  • Run GC: Executes garbage collection on the selected member. A notification stating that the GC execution was successful is shown.

  • Thread Dump: Takes a thread dump of the selected member and shows it in a separate dialog.

  • Shutdown Member: Shuts down the selected member.

  • Promote Member: If the member is a lite member, this button promotes it to a data member.

Graphs

The Heap and Native Memory chart shows the percentage of CPU usage on the selected member. The CPU Load and Used Memory chart shows the memory usage on the selected member. You can open each chart as a separate dialog using the maximize maximize button.

To customize the data displayed in the graphs, see Graphs

Runtime

Runtime is a dynamically updated window tab showing the processor number, the start and up times, and the maximum, total and free memory sizes of the selected member. These values are collected from the default MXBeans in the Java Virtual Machine (JVM).

These descriptions may vary according to the JVM version or vendor.
Table 2. Member runtime statistics
Field Description

Number of Processors

Number of processors available to the member (JVM).

Start Time

Start time of the member (JVM).

Uptime

Uptime of the member (JVM).

Maximum Memory

Maximum amount of memory that the member (JVM) will attempt to use.

Free Memory

Amount of free memory in the member (JVM).

Used Heap Memory

Amount of used memory.

Max Heap Memory

Maximum amount of memory that can be used for memory management.

Used Non-Heap Memory

Amount of used memory.

Max Non-Heap Memory

Maximum amount of memory that can be used for memory management.

Total Loaded Classes

Total number of classes that have been loaded since the member (JVM) has started execution.

Current Loaded Classes

Number of classes that are currently loaded in the member (JVM).

Total Unloaded Classes

Total number of classes unloaded since the member (JVM) has started execution.

Total Thread Count

Total number of threads created and also started since the member (JVM) started.

Active Thread Count

Current number of live threads including both daemon and non-daemon threads.

Peak Thread Count

Peak live thread count since the member (JVM) started or peak was reset.

Daemon Thread Count

Current number of live daemon threads.

OS Free Physical Memory

Amount of free physical memory.

OS Committed Virtual Memory

Amount of virtual memory that is guaranteed to be available to the running process.

OS Total Physical Memory

Total amount of physical memory.

OS Free Swap Space

Amount of free swap space. Swap space is used when the amount of physical memory (RAM) is full. If the system needs more memory resources and the RAM is full, inactive pages in memory are moved to the swap space.

OS Total Swap Space

Total amount of swap space.

OS Maximum File Descriptor Count

Maximum number of file descriptors. File descriptor is an integer number that uniquely represents an opened file in the operating system.

OS Open File Descriptor Count

Number of open file descriptors.

OS Process CPU Time

CPU time used by the process on which the member (JVM) is running.

OS Process CPU Load

Recent CPU usage for the member (JVM) process. This is a double with a value from 0.0 to 1.0. A value of 0.0 means that none of the CPUs were running threads from the member (JVM) process during the recent period of time observed, while a value of 1.0 means that all CPUs were actively running threads from the member (JVM) 100% of the time during the recent period being observed. Threads from the member (JVM) include the application threads as well as the member (JVM) internal threads.

OS System Load Average

System load average for the last minute. The system load average is the average over a period of time of this sum: (the number of runnable entities queued to the available processors) + (the number of runnable entities running on the available processors). The way in which the load average is calculated is operating system specific but it is typically a damped time-dependent average.

OS System CPU Load

Recent CPU usage for the whole system represented as a percentage value. 0% means that all CPUs were idle during the recent period of time observed, while 100% means that all CPUs were actively running during the recent period being observed.

Properties

Next to the Runtime tab, the Properties tab shows the member’s system properties.

Member Configuration

Management Center receives the member configuration in XML format. As a result, even if you used a different configuration format such as YAML, it will be displayed in XML.

To view a member’s configuration:

  1. Click a member’s row in the table.

  2. Scroll down to Member Configuration at the bottom of the page.

Slow Operations

If a member has slow operations, you can view the detected slow operations which occurred on that member. The data is collected by the SlowOperationDetector.

To view slow operations for a member:

  1. Click a member’s row in the table.

  2. Click on an entry in the List of Slow Operations table.

Slow Operations Details