Memory Usage: /Documentation

Memory Usage

Documentation

Memory Usage

The Memory Usage page shows information about current memory utilization within the LabKey Server process. This information can be useful in identifying problematic settings or processes. Access it via: (Admin) > Site > Admin Console > Diagnostics > Memory Usage.

Memory Graphs

The top section of the page shows graphs of the various memory spaces within the Java Virtual Machine, including their current utilization and their maximum size. The Heap and Metaspace sections are typically the most likely to hit their maximum size.

Total Heap Memory
Total Non-heap Memory
CodeHeap 'non-nmethods' Non-heap memory
Metaspace Non-heap memory
CodeHeap 'profiled nmethods'
Compressed Class Space Non-heap memory
G1 Eden Space Heap memory
G1 Old Gen Heap memory
G1 Survivor Space Heap memory
CodeHeap 'non-profiled nmethods' Non-heap memory
Buffer pool mapped
Buffer pool direct
Buffer pool mapped - 'non-volatile memory'

Memory Stats

Detailed stats about the pools available (shown above). Their initial size, amount used, amount committed, and max setting. This section also includes a list of system property names and their values.

Loaded Class Count
Unloaded Class Count
Total Loaded Class Count
VM Start Time
VM Uptime
VM Version
VM Classpath
Thread Count
Peak Thread Count
Deadlocked Thread Count
G1 Young Generation GC count
G1 Young Generation GC time
G1 Old Generation GC count
G1 Old Generation GC time
CPU count
Total OS memory
Free OS memory
OS CPU load
JVM CPU load

In-Use Objects

When the server is running with Java asserts enabled (via the -ea parameter on the command-line), the bottom of the page will show key objects that are tracked to ensure that they are not causing memory leaks. This is not a recommended configuration for production servers.

Links

The links at the top of the page allow an administrator to clear caches and garbage collect (gc):

Clear caches, gc and refresh
Gc and refresh
Refresh

Garbage collection will free memory claimed by unused objects. This can be useful to see how much memory is truly in use at a given point in time.

LabKey develops, tests, and deploys using the default Java garbage collector. Explicitly specifying an alternative garbage collector is not recommended.