[CASSANDRA-19779] direct IO support is always evaluated to false upon the very first start of a node

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 5.0-rc2, 5.0.1, 5.1
• Component/s: Legacy/Tools
• Bug Category: Code
• Severity: Low
• Complexity: Low Hanging Fruit
• Discovered By: Adhoc Test
• Platform: All
• Since Version: 5.0-alpha1

Source Control Link

https://github.com/apache/cassandra/commit/5ab976d796471a1ecdf3596a148a3e4b8c1a982e

Test and Documentation Plan

CI

• Assignee: Stefan Miklosovic
• Reporter: Stefan Miklosovic

Authors

Stefan Miklosovic

Reviewers

Branimir Lambov, Maxwell Guo

• Created: 18/Jul/24 12:53
• Updated: 09/Aug/24 09:30
• Resolved: 05/Aug/24 00:14

Description

When I extract the distribution tarball and I want to use tools in tools/bin, there is this warn log visible every time for tools when they are started (does not happen on "help" command, obviously)

WARN  14:25:11,835 Unable to determine block size for commit log directory: null 

This is because we introduced this (1) in CASSANDRA-18464

What that does is that it will go and try to create a temporary file in commit log directory to get "block size" for a "file store" that file is in.

The problem with that is that when we just extract a tarball and run the tools - Cassandra was never started - then such commit log directory does not exist yet, so it tries to create a temporary file in a non-existing directory, which fails, hence the log message.

The fix is to check if commitlog dir exists and return / skip the resolution of block size if it does not.

Another approach might be to check if this is executed in the context of a tool and skip it from resolution altogether. The problem with this is that not all tools we have in bin/log call DatabaseDescriptor.
toolInitialization() so we might combine these two.
(1) https://github.com/apache/cassandra/blob/cassandra-5.0/src/java/org/apache/cassandra/config/DatabaseDescriptor.java#L1455-L1462

Issue Links

• causes: CASSANDRA-19820 Fix tests extending FuzzTestBase when running test-compression profile
• is caused by: CASSANDRA-18464 Enable Direct I/O For CommitLog Files
• links to: GitHub Pull Request #3445
• links to: GitHub Pull Request #3446
• links to: patch CASSANDRA-19779 5.0
• links to: patch CASSANDRA-19779 5.0.0
• links to: patch CASSANDRA-19779 trunk