Minecraft:Commands/jfr - Revision history

SyncBot: Fix template calls: add MC/ prefix

2026-04-09T20:11:42Z

Fix template calls: add MC/ prefix

← Older revision		Revision as of 20:11, 9 April 2026
Line 1:		Line 1:
	{{Exclusive\|java}}		{{MC/Exclusive\|java}}

	{{Infobox command		{{Infobox command
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	}}		}}

	Starts and stops profiling with {{w\|Java Flight Recorder}} ([https://openjdk.java.net/jeps/328 JEP]) as well as a few custom events.		Starts and stops profiling with {{MC/W\|Java Flight Recorder}} ([https://openjdk.java.net/jeps/328 JEP]) as well as a few custom events.

	==Usage==		==Usage==
	When profiling, it records several information about CPU, memory, and threads usage of the client while it was running, and saves them on a <code>.jfr</code> file under the {{cd\|.minecraft/debug}} folder.		When profiling, it records several information about CPU, memory, and threads usage of the client while it was running, and saves them on a <code>.jfr</code> file under the {{MC/Cd\|.minecraft/debug}} folder.

	The file can be opened using an external tool or software, such as [https://visualvm.github.io/ VisualVM] or [https://github.com/openjdk/jmc JMC]. It contains JVM and operating system events, with several ''Minecraft''-related custom events below:		The file can be opened using an external tool or software, such as [https://visualvm.github.io/ VisualVM] or [https://github.com/openjdk/jmc JMC]. It contains JVM and operating system events, with several ''Minecraft''-related custom events below:
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	== Output ==		== Output ==
	{{Output table}}		{{MC/Output table}}
	{{Output table\|edition=je\|On fail\|N/A\|0\|0}}		{{MC/Output table\|edition=je\|On fail\|N/A\|0\|0}}
	{{Output table\|On success\|N/A\|1\|1}}		{{MC/Output table\|On success\|N/A\|1\|1}}
	{{Output table}}		{{MC/Output table}}

	== History ==		== History ==
	{{HistoryTable		{{HistoryTable
	\|{{HistoryLine\|java}}		\|{{MC/HistoryLine\|java}}
	\|{{HistoryLine\|\|1.18\|dev=21w37a\|Added {{~~cmd~~\|jfr\|link=none}}.}}		\|{{HistoryLine\|\|1.18\|dev=21w37a\|Added {{MC/Cmd\|jfr\|link=none}}.}}
	}}		}}

	== Navigation ==		== Navigation ==
	{{Navbox commands}}		{{MC/Navbox commands}}

	de:Befehl/jfr		de:Befehl/jfr

SyncBot: Remove broken links to missing pages

2026-04-09T15:44:34Z

Remove broken links to missing pages

← Older revision		Revision as of 15:44, 9 April 2026
Line 9:		Line 9:

	==Usage==		==Usage==
	When profiling, it records several information about CPU, memory, and threads usage of the client while it was running, and saves them on a <code>.jfr</code> file under the {{cd\|~~[[Minecraft:~~.minecraft]]/debug}} folder.		When profiling, it records several information about CPU, memory, and threads usage of the client while it was running, and saves them on a <code>.jfr</code> file under the {{cd\|.minecraft/debug}} folder.

	The file can be opened using an external tool or software, such as [https://visualvm.github.io/ VisualVM] or [https://github.com/openjdk/jmc JMC]. It contains JVM and operating system events, with several ''Minecraft''-related custom events below:		The file can be opened using an external tool or software, such as [https://visualvm.github.io/ VisualVM] or [https://github.com/openjdk/jmc JMC]. It contains JVM and operating system events, with several ''Minecraft''-related custom events below:
	<!-- Documentation with names taken from VisualVM program -->		<!-- Documentation with names taken from VisualVM program -->
	* '''Network''' group, which contains:		* '''Network''' group, which contains:
	**'''Network Packet Received''' and '''Network Packet Sent''': network packet events, containing information about their protocol ID, packet ID, packet direction (server or client bound), remote address, and bytes size. See ~~[[Minecraft:~~Java Edition protocol]] for list of protocol and packet IDs.		**'''Network Packet Received''' and '''Network Packet Sent''': network packet events, containing information about their protocol ID, packet ID, packet direction (server or client bound), remote address, and bytes size. See Java Edition protocol for list of protocol and packet IDs.
	**'''Network Summary''': summary information of received and sent packets count and their bytes size.		**'''Network Summary''': summary information of received and sent packets count and their bytes size.

	* '''Storage''' group, which contains:		* '''Storage''' group, which contains:
	** '''Region File Read''' and '''Region File Write'''~~: [[Minecraft~~:region file]] events, containing information about region and chunk positions, dimension, and type of compression algorithm.		** '''Region File Read''' and '''Region File Write''': region file events, containing information about region and chunk positions, dimension, and type of compression algorithm.

	* '''Ticking''' group, which only contains a single custom event:		* '''Ticking''' group, which only contains a single custom event:
Line 24:		Line 24:

	*'''World Generation''' group, which contains:		*'''World Generation''' group, which contains:
	**'''Chunk Generation''': time taken to generate individual ~~[[Minecraft:~~chunk]] stages.		**'''Chunk Generation''': time taken to generate individual chunk stages.
	**'''Create/Load World''': initial ~~[[Minecraft:~~world]] loading duration when loading a world.		**'''Create/Load World''': initial world loading duration when loading a world.

	The <code>.jfr</code> file is accompanied by a summary [[Minecraft:JSON]] report is written both to the log file and in the debug folder.		The <code>.jfr</code> file is accompanied by a summary [[Minecraft:JSON]] report is written both to the log file and in the debug folder.
Line 58:		Line 58:
	{{Navbox commands}}		{{Navbox commands}}

	~~[[Minecraft:~~de:Befehl/jfr]]		de:Befehl/jfr
	~~[[Minecraft:~~es:Comandos/jfr]]		es:Comandos/jfr
	~~[[Minecraft:~~ja:コマンド/jfr]]		ja:コマンド/jfr
	~~[[Minecraft:~~lzh:令/jfr]]		lzh:令/jfr
	~~[[Minecraft:~~pt:Comandos/jfr]]		pt:Comandos/jfr
	~~[[Minecraft:~~zh:命令/jfr]]		zh:命令/jfr

imported>Outrowed: separate WP and JEP linking

2025-03-30T03:47:01Z

separate WP and JEP linking

New page

{{Exclusive|java}}

{{Infobox command
|name=jfr
|oplevel=4
}}

Starts and stops profiling with {{w|Java Flight Recorder}} ([https://openjdk.java.net/jeps/328 JEP]) as well as a few custom events.

==Usage==
When profiling, it records several information about CPU, memory, and threads usage of the client while it was running, and saves them on a <code>.jfr</code> file under the {{cd|[[Minecraft:.minecraft]]/debug}} folder.

The file can be opened using an external tool or software, such as [https://visualvm.github.io/ VisualVM] or [https://github.com/openjdk/jmc JMC]. It contains JVM and operating system events, with several ''Minecraft''-related custom events below:

* '''Network''' group, which contains:
**'''Network Packet Received''' and '''Network Packet Sent''': network packet events, containing information about their protocol ID, packet ID, packet direction (server or client bound), remote address, and bytes size. See [[Minecraft:Java Edition protocol]] for list of protocol and packet IDs.
**'''Network Summary''': summary information of received and sent packets count and their bytes size.

* '''Storage''' group, which contains:
** '''Region File Read''' and '''Region File Write''': [[Minecraft:region file]] events, containing information about region and chunk positions, dimension, and type of compression algorithm.

* '''Ticking''' group, which only contains a single custom event:
**'''Server Tick Time''': sampling event of the average server tick duration at one second intervals.

*'''World Generation''' group, which contains:
**'''Chunk Generation''': time taken to generate individual [[Minecraft:chunk]] stages.
**'''Create/Load World''': initial [[Minecraft:world]] loading duration when loading a world.

The <code>.jfr</code> file is accompanied by a summary [[Minecraft:JSON]] report is written both to the log file and in the debug folder.

== Syntax ==
:<code>jfr start</code>
:: Start JFR profiling.
:<code>jfr stop</code>
:: Stop JFR profiling.

== Result ==
{{Result table|onlyje=1}}
{{Result table|The command is incomplete, or any argument is not specified correctly.|unparseable}}
{{Result table|cmd=/jfr start|A jfr profiler has already been started.|fail}}
{{Result table|cmd=/jfr stop|There's no jfr profiler running.}}
{{Result table|cmd=|succeed}}
{{Result table}}

== Output ==
{{Output table}}
{{Output table|edition=je|On fail|N/A|0|0}}
{{Output table|On success|N/A|1|1}}
{{Output table}}

== History ==
{{HistoryTable
|{{HistoryLine|java}}
|{{HistoryLine||1.18|dev=21w37a|Added {{cmd|jfr|link=none}}.}}
}}

== Navigation ==
{{Navbox commands}}

[[Minecraft:de:Befehl/jfr]]
[[Minecraft:es:Comandos/jfr]]
[[Minecraft:ja:コマンド/jfr]]
[[Minecraft:lzh:令/jfr]]
[[Minecraft:pt:Comandos/jfr]]
[[Minecraft:zh:命令/jfr]]