[HDDS-2929] Implement ofs://: temp directory mount

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.0.0
• Labels: pull-request-available
• Assignee: Siyao Meng
• Reporter: Siyao Meng
• Created: 22/Jan/20 22:04
• Updated: 30/Sep/21 09:51
• Resolved: 07/Mar/20 01:33

Description

Because of ofs:// filesystem hierarchy starts with volume then bucket, an application typically won't be able to write directly under a first-level folder, e.g. ofs://service-id1/tmp/. /tmp/ is a special case that we need to handle since that is the default location most legacy Hadoop applications write to for swap/temporary files. In order to address this, we would introduce /tmp/ as a client-side "mount" to another Ozone bucket.

Note that the preliminary implementation would only allow for /tmp/ to be a mount but not any user-defined path.

This depends on HDDS-2840 and HDDS-2928.

Issue Links

• causes: HDDS-5801 ofs temp implementation different from design doc
• links to: GitHub Pull Request #610