[
https://issues.apache.org/jira/browse/CASSANDRA-16071?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17235421#comment-17235421
]
Michael Semb Wever commented on CASSANDRA-16071:
------------------------------------------------
[~scott_carey], apologies for moving ahead with the upgrade protection patch
before getting the feedback from you.
We definitely hear your concerns and pain around how to upgrade in this
situation while maintaining the SASI available.
The approach of reverting to the default was chosen to minimise tech debt in
the C* code, as having it continue to parse bytes is something likely to trap
other C* developers and might just hurt other users down the road. The impact
is also thought to be limited, i.e. not many will be in this situation of
accurately incorrectly tuned max_compaction_flush_memory_in_mb in setups where
the default value does not work at all and SASI availability is critical.
That being said, I will write up here soon a manual migration approach you can
use to avoid having to recreate the SASI and keeping it available over the
upgrade.
> max_compaction_flush_memory_in_mb is interpreted as bytes
> ---------------------------------------------------------
>
> Key: CASSANDRA-16071
> URL: https://issues.apache.org/jira/browse/CASSANDRA-16071
> Project: Cassandra
> Issue Type: Bug
> Components: Feature/SASI
> Reporter: Michael Semb Wever
> Assignee: Michael Semb Wever
> Priority: Normal
> Fix For: 4.0, 3.11.8, 4.0-beta2, 4.0-beta4, 3.11.10
>
>
> In CASSANDRA-12662, [~scottcarey]
> [reported|https://issues.apache.org/jira/browse/CASSANDRA-12662?focusedCommentId=17070055&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-17070055]
> that the {{max_compaction_flush_memory_in_mb}} setting gets incorrectly
> interpreted in bytes rather than megabytes as its name implies.
> {quote}
> 1. the setting 'max_compaction_flush_memory_in_mb' is a misnomer, it is
> actually memory in BYTES. If you take it at face value, and set it to say,
> '512' thinking that means 512MB, you will produce a million temp files
> rather quickly in a large compaction, which will exhaust even large values of
> max_map_count rapidly, and get the OOM: Map Error issue above and possibly
> have a very difficult situation to get a cluster back into a place where
> nodes aren't crashing while initilaizing or soon after. This issue is minor
> if you know about it in advance and set the value IN BYTES.
> {quote}
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
