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https://issues.apache.org/jira/browse/HDFS-17772?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Xiaoqiao He resolved HDFS-17772.
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Fix Version/s: 3.5.0
(was: 3.4.2)
Hadoop Flags: Reviewed
Target Version/s: (was: 3.4.2)
Resolution: Fixed
> The JournaledEditsCache has an int overflow issue, causing the maximum
> capacity to always be Integer MAX_VALUE
> --------------------------------------------------------------------------------------------------------------
>
> Key: HDFS-17772
> URL: https://issues.apache.org/jira/browse/HDFS-17772
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: namenode
> Affects Versions: 3.4.2
> Reporter: Guo Wei
> Assignee: Guo Wei
> Priority: Minor
> Labels: pull-request-available
> Fix For: 3.5.0
>
>
> When we use the RBF SBN READ in the production environment, we found the
> following issue.
> HDFS-16550 provides the parameter `dfs.journalnode.edit-cache-size.bytes` to
> control cache size based on journalnode memory ratio, but there is an issue
> of int overflow:
> HDFS-16550 When using the `dfs.journalnode.edit-cache-size.bytes` parameter
> to control cache capacity, during the initialization of the `capacity` in
> `org.apache.hadoop.hdfs.qjournal.server.JournaledEditsCache#JournaledEditsCache`,
> a long-to-int overflow issue occurs. For instance, when the heap memory is
> configured as 32GB (where `Runtime.getRuntime().maxMemory()` returns
> 30,542,397,440 bytes), the overflow results in the `capacity` being truncated
> to `Integer.MAX_VALUE` (2,147,483,647). This renders the parameter setting
> ineffective, as the intended proportional cache capacity cannot be achieved.
> To resolve this, the `capacity` should be declared as a `long` type, and the
> `totalSize` variable should also be converted to a `long` type to prevent
> overflow in scenarios where `capacity` exceeds 2,147,483,647, ensuring both
> variables can accurately represent large values without integer limitations.
> The error situation is as follows:
> {code:java}
> // code placeholder
> the dfs.Journalnode.edit-cache-size.fraction parameter uses the default value
> of 0.5f. I configured the heap memory size of Journalnode to 30,542,397,440
> bytes, and expected it to be 15,271,198,720 bytes, but the capacity size is
> always Integer.MAX_VALUE=2,147,483,647 bytes
> 2025-04-15 14:14:03,970 INFO server.Journal
> (JournaledEditsCache.java:<init>(144)) - Enabling the journaled edits cache
> with a capacity of bytes: 2147483647
> The repaired result is as follows，meet expectation:
> 2025-04-15 16:04:44,840 INFO server.Journal
> (JournaledEditsCache.java:<init>(144)) - Enabling the journaled edits cache
> with a capacity of bytes: 15271198720 {code}
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