[YARN-5312] Parameter 'size' in the webservices "/containerlogs/$containerid/$filename" and in AHSWebServices is semantically confusing

• Type: Sub-task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Assignee: Vinod Kumar Vavilapalli
• Reporter: Vinod Kumar Vavilapalli
• Created: 05/Jul/16 18:17
• Updated: 27/Jul/16 02:40

Description

This got added in YARN-5088 and I found this while reviewing YARN-5224.

Also, the parameter 'size' in the API "/containerlogs/$containerid/$filename" and similarly in AHSWebServices is confusing with semantics. I think we are better off with an offset and size.

An offset (in bytes, +ve to indicate from the start and -ve to indicate from the end) together with a size (in bytes) indicating how much to read from the offset are a better combination - this is how most file-system APIs look like, for comparison.

I can also imagine number of lines as a better unit than bytes for offset and size - perhaps yet another ticket.

/cc vvasudev.

Issue Links

• is broken by: YARN-5088 Improve "yarn log" command-line to read the last K bytes for the log files
• is related to: YARN-5224 Logs for a completed container are not available in the yarn logs output for a live application