Fix Statement leak in Trino JDBC DatabaseMetaData#10632
Merged
findepi merged 5 commits intotrinodb:masterfrom Jan 18, 2022
Merged
Fix Statement leak in Trino JDBC DatabaseMetaData#10632findepi merged 5 commits intotrinodb:masterfrom
findepi merged 5 commits intotrinodb:masterfrom
Conversation
findepi
force-pushed
the
findepi/jdbc-statement-leak
branch
from
7d3baed to
b5f7337
Compare
nineinchnick
approved these changes
Jan 15, 2022
electrum
approved these changes
Jan 16, 2022
Member
electrum
left a comment
electrum
left a comment
There was a problem hiding this comment.
Nice, this is better than my first idea of a weak reference
client/trino-jdbc/src/main/java/io/trino/jdbc/AbstractTrinoResultSet.java
Outdated
Show resolved
Hide resolved
client/trino-jdbc/src/main/java/io/trino/jdbc/TrinoDatabaseMetaData.java
Outdated
Show resolved
Hide resolved
client/trino-jdbc/src/main/java/io/trino/jdbc/TrinoResultSet.java
Outdated
Show resolved
Hide resolved
client/trino-jdbc/src/main/java/io/trino/jdbc/TrinoResultSet.java
Outdated
Show resolved
Hide resolved
client/trino-jdbc/src/main/java/io/trino/jdbc/TrinoResultSet.java
Outdated
Show resolved
Hide resolved
client/trino-jdbc/src/test/java/io/trino/jdbc/TestTrinoDatabaseMetaData.java
Outdated
Show resolved
Hide resolved
`AsyncIterator.cancel` is idempotent (future cancellation) and `client.close()` is idempotent too (state atomic swap controls that), so this is not a behavioral change, but necessary for further code evolution.
It's somewhat more readable if the mutable state, especially one that needs to be updated with thread-safety in mind, is confined to a class.
Before the change, Trino JDBC's `DatabaseMetaData` implementation (`TrinoDatabaseMetaData`) would create `Statement` objects that are never closed. Since `Connection` (`TrinoConnection`) tracks open statements to be able to close them upon `Connection.close()` (per JDBC requirements), this created a memory leak where `Statement` objects are leaked in `Connection.statements` collection. The commit fixing this, under the condition that `ResultSet` returned from `TrinoDatabaseMetaData` is correctly closed.
findepi
force-pushed
the
findepi/jdbc-statement-leak
branch
from
b5f7337 to
bea351b
Compare
kokosing
approved these changes
Jan 17, 2022
Member
Author
Closed
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
4 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Before the change, Trino JDBC's
DatabaseMetaDataimplementation(
TrinoDatabaseMetaData) would createStatementobjects that arenever closed. Since
Connection(TrinoConnection) tracks openstatements to be able to close them upon
Connection.close()(per JDBCrequirements), this created a memory leak where
Statementobjects areleaked in
Connection.statementscollection.The commit fixing this, under the condition that
ResultSetreturnedfrom
TrinoDatabaseMetaDatais correctly closed.Fixes #10584