[jira] [Created] (IGNITE-19412) Potential memory leak in MailboxRegistryImpl under intensive SQL load

["Andrey Khitrin (Jira)" <ji...@apache.org>]

Andrey Khitrin created IGNITE-19412:
---------------------------------------

             Summary: Potential memory leak in MailboxRegistryImpl under intensive SQL load
                 Key: IGNITE-19412
                 URL: https://issues.apache.org/jira/browse/IGNITE-19412
             Project: Ignite
          Issue Type: Bug
          Components: sql
    Affects Versions: 3.0.0-beta1
            Reporter: Andrey Khitrin
         Attachments: Screenshot_20230503_172458.png, ddl-ignite3.sql, java_pid4802_Leak_Suspects.zip

I tried to run a SQL benchmark (slightly modified [Benchbase TPC-C scenario|https://github.com/cmu-db/benchbase/wiki/TPC-C]) against Ignite3 (commit hash b48ddcba7cd2bd3b9a053ae131c25b44a0400e27).

Ignite3 was running with -Xmx6G -Xms6G memory limit. After some time it has reached memory limits and failed due to OutOfMemoryError. A heap dump was generated on failure. I can't attach this dump due to its size, but I've opened it in MAT and created a report (see zip file attached).

The report says that most of the retained heap (almost 5G) is occupied by a single instance of o.a.i.internal.sql.engine.exec.MailboxRegistryImpl class (see image attached).

{*}Hypothesis{*}: on an intense load, MailboxRegistryImpl creates a lot of lambda expressions. This happens faster than they're being utilized. With limited memory size, it could lead to OOM at some moment.

Benchmark is quite trivial by mechanics:

1. Create a table structure (see DDL file attached)
2. Fill tables with randomized data (several tens of thousands rows is enough)
3. Run select queries in a loop (actually, it wouldn't happen; OOM was raised on data insertion).



--
This message was sent by Atlassian Jira
(v8.20.10#820010)