[HBASE-8671] Per-region WAL breaks CP backwards compatibility in 0.94 for non-enabled case

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.94.9
• Fix Version/s: 0.94.9
• Assignee: Jesse Yates
• Reporter: Jesse Yates
• Created: 31/May/13 22:41
• Updated: 04/Jul/13 22:10
• Resolved: 04/Jun/13 02:20

Description

Moving from a single WAL to the possibility of multiple WALs, the method signature in RegionServerServices became:

  /** @return the HLog for a particular region. Pass null for getting the
   * default (common) WAL */
  public HLog getWAL(HRegionInfo regionInfo) throws IOException;

However, CPs that previously needed access to the WAL would just call:

RegionServerServices.getWAL();

Which is equivalent to calling:

RegionServerServices.getWAL(null);

but which requires a code change, recompilation, and possibly an additional compatibility layer for different versions of 0.94... not a great situation.