system-gc-logs

Retrieves JVM GC log entries. Cluster administrator permission is required.

Command properties

Property	Description
Command type	Driver query
Required permission	Cluster administrator
License usage	Not counted
Parallel execution	Not supported
Distributed execution	Not supported

Syntax

system-gc-logs [fastcheck=BOOL] [duration=INT{mon|w|d|h|m|s}] [from=DATE] [to=DATE]

Options

fastcheck=BOOL: Quickly scans and outputs only lines that indicate potential GC problems. When set to t, only lines of type Allocation Stall, To-space Exhausted, and Pause Full are output. (Default: f)
duration=INT{mon|w|d|h|m|s}: Limits results to GC logs within the specified time range from the current time. Use units mon (month), w (week), d (day), h (hour), m (minute), or s (second). For example, 10s means the last 10 seconds relative to query execution time. Cannot be used when both from and to options are specified.
from=DATE: Start time of the retrieval range, in yyyy[MM[dd[HH[mm[ss]]]]] format. If month, day, etc. are omitted, the earliest possible time is used. The start time is included in the results.
to=DATE: End time of the retrieval range, in yyyy[MM[dd[HH[mm[ss]]]]] format. If month, day, etc. are omitted, the earliest possible time is used. The end time is not included in the results.

Output fields

Field	Type	Description
_time	timestamp	GC log timestamp
type	string	GC log type. One of `ALLOC_STALL`, `TO_SPACE_EXHAUSTED`, `FULL_GC`, or `RAW`.
duration	double	GC execution time (milliseconds). Returned only for `ALLOC_STALL` or `FULL_GC` type.
level	string	GC log severity level
msg	string	GC log message body. Returned when the log format is `[timestamp][level] message`.
line	string	Original GC log line. Returned for unparseable formats or `RAW` type.

Error codes

Parsing errors

Error code	Message	Description
95020	No read permission. Cluster administrator permission is required.	The user does not have cluster administrator permission
95030	Invalid from value.	The `from` option value cannot be parsed as a date
95031	Invalid to value.	The `to` option value cannot be parsed as a date
95032	Invalid from value.	The `to` value is earlier than the `from` value
95023	Cannot use duration option when both from and to options are specified.	`duration` was used while both `from` and `to` were specified
95131	Invalid fastcheck value: [value]	A non-boolean value was specified for the `fastcheck` option

Runtime errors

N/A

Description

The system-gc-logs command reads the JVM GC log file (gc.log) and retrieves GC log entries.

Using the fastcheck=t option, you can quickly retrieve only entries that indicate potential GC problems (Allocation Stall, To-space Exhausted, Pause Full). With fastcheck=t, the type field returns the corresponding type, and if a GC execution time is available, the duration field returns it in milliseconds.

When you specify a time range with the from and to options, only GC log files within that range are selectively read.

Cluster administrator permission is required to run this command.

Examples

Retrieve all GC logs
```
system-gc-logs
```
Retrieves all JVM GC logs.
Quickly retrieve only problematic GC entries
```
system-gc-logs fastcheck=t
```
Retrieves only GC log entries of types Allocation Stall, To-space Exhausted, and Pause Full.
Retrieve GC logs from the last hour
```
system-gc-logs duration=1h
```
Retrieves GC logs from within the last hour.

Analyze Full GC frequency

system-gc-logs fastcheck=t duration=1d
| search type == "FULL_GC"
| stats count() as cnt, avg(duration) as avg_ms

Retrieves the number of Full GC occurrences and average execution time over the last day.