docs/en/developers/jemalloc_heap_profile.md
This topic describes how to enable and visualize the Jemalloc Heap Profile for StarRocks.
:::note
Syntax:
ADMIN EXECUTE ON <be_id> 'System.print(HeapProf.getInstance().enable_prof())'
be_id: The ID of BE/CN node. You can get the ID by running SHOW BACKENDS or SHOW COMPUTE NODES.
Example:
mysql> admin execute on 10001 'System.print(HeapProf.getInstance().enable_prof())';
+----------------------+
| result |
+----------------------+
| instance of HeapProf |
+----------------------+
1 row in set (0.00 sec)
You can check whether Jemalloc Heap Profile is enabled or not by using the following syntax:
ADMIN EXECUTE ON <be_id> 'System.print(HeapProf.getInstance().has_enable())'
Example:
mysql> admin execute on 10001 'System.print(HeapProf.getInstance().has_enable())';
+--------+
| result |
+--------+
| true |
+--------+
1 row in set (0.01 sec)
You can disable Jemalloc Heap Profile by using the following syntax:
ADMIN EXECUTE ON <be_id> 'System.print(HeapProf.getInstance().disable_prof())'
Example:
mysql> admin execute on 10001 'System.print(HeapProf.getInstance().disable_prof())';
+----------------------+
| result |
+----------------------+
| instance of HeapProf |
+----------------------+
1 row in set (0.00 sec)
Syntax:
ADMIN EXECUTE ON <be_id> 'System.print(HeapProf.getInstance().dump_dot_snapshot())'
Example:
mysql> admin execute on 10001 'System.print(HeapProf.getInstance().dump_dot_snapshot())';
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| result |
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| digraph "/home/disk/opt/env/default/be/lib/starrocks_be; 1.0 MB" { |
| node [width=0.375,height=0.25]; |
| Legend [shape=box,fontsize=24,shape=plaintext,label="/home/disk/opt/env/default/be/lib/starrocks_be\lTotal MB: 1.0\lFocusing on: 1.0\lDropped nodes with <= 0.0 abs(MB)\lDropped edges with <= 0.0 MB\l"]; |
| N1 [label="brpc\nInputMessenger\nOnNewMessages\n0.0 (0.0%)\rof 1.0 (100.0%)\r",shape=box,fontsize=8.0]; |
| N2 [label="brpc\nSocket\nProcessEvent\n0.0 (0.0%)\rof 1.0 (100.0%)\r",shape=box,fontsize=8.0]; |
| N3 [label="bthread\nTaskGroup\ntask_runner\n0.0 (0.0%)\rof 1.0 (100.0%)\r",shape=box,fontsize=8.0]; |
| N4 [label="bthread_make_fcontext\n0.0 (0.0%)\rof 1.0 (100.0%)\r",shape=box,fontsize=8.0]; |
| N5 [label="brpc\nInputMessenger\nCutInputMessage\n0.0 (0.0%)\rof 0.5 (50.1%)\r",shape=box,fontsize=8.0]; |
| N6 [label="brpc\npolicy\nParseRpcMessage\n0.5 (50.1%)\r",shape=box,fontsize=43.4]; |
| N7 [label="brpc\nProcessInputMessage\n0.0 (0.0%)\rof 0.5 (49.9%)\r",shape=box,fontsize=8.0]; |
| N8 [label="brpc\npolicy\nProcessRpcRequest\n0.0 (0.0%)\rof 0.5 (49.9%)\r",shape=box,fontsize=8.0]; |
| N9 [label="starrocks\nPInternalServiceImplBase\nexecute_command\n0.0 (0.0%)\rof 0.5 (49.9%)\r",shape=box,fontsize=8.0]; |
| N10 [label="starrocks\nStorageEngineRef\nbind\n0.0 (0.0%)\rof 0.5 (49.9%)\r",shape=box,fontsize=8.0]; |
| N11 [label="starrocks\nexecute_command\n0.0 (0.0%)\rof 0.5 (49.9%)\r",shape=box,fontsize=8.0]; |
| N12 [label="starrocks\nexecute_script\n0.0 (0.0%)\rof 0.5 (49.9%)\r",shape=box,fontsize=8.0]; |
| N13 [label="std\nmake_unique\n0.5 (49.9%)\r",shape=box,fontsize=43.3]; |
| N2 -> N1 [label=1.0, weight=16398, style="setlinewidth(2.000000)"]; |
| N3 -> N2 [label=1.0, weight=16398, style="setlinewidth(2.000000)"]; |
| N4 -> N3 [label=1.0, weight=16398, style="setlinewidth(2.000000)"]; |
| N1 -> N5 [label=0.5, weight=10102, style="setlinewidth(2.000000)"]; |
| N5 -> N6 [label=0.5, weight=10102, style="setlinewidth(2.000000)"]; |
| N9 -> N11 [label=0.5, weight=10086, style="setlinewidth(2.000000)"]; |
| N12 -> N10 [label=0.5, weight=10086, style="setlinewidth(2.000000)"]; |
| N11 -> N12 [label=0.5, weight=10086, style="setlinewidth(2.000000)"]; |
| N1 -> N7 [label=0.5, weight=10086, style="setlinewidth(2.000000)"]; |
| N7 -> N8 [label=0.5, weight=10086, style="setlinewidth(2.000000)"]; |
| N10 -> N13 [label=0.5, weight=10086, style="setlinewidth(2.000000)"]; |
| N8 -> N9 [label=0.5, weight=10086, style="setlinewidth(2.000000)"]; |
| } |
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
29 rows in set (30.22 sec)
Copy the profile text you collected in the last step, and paste it to GraphvizOnline.
You can then download the visualized Heap Profile.
Example: