Alex Behm has posted comments on this change. Change subject: IMPALA-4172: Switch to BlockLocation methods for disk IDs ......................................................................
Patch Set 1: (1 comment) http://gerrit.cloudera.org:8080/#/c/4914/1/fe/src/main/java/org/apache/impala/catalog/HdfsTable.java File fe/src/main/java/org/apache/impala/catalog/HdfsTable.java: Line 379: private static int getDiskId(String storageId) { > it's very unusual for a server to have more than 128 disks (i don't think w the UUIDs are generated randomly and we hash those, so it's possible we get a series of disk IDs which when modded all land on the same disk queue for example, we could get hashes 8, 16, 24, 32, etc. on a machine with 8 disks Of course, in aggregate these collisions are unlikely, but like you said a single machine has few disks, so I think this effect can easily happen on a single machine. -- To view, visit http://gerrit.cloudera.org:8080/4914 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: Ibbff94cef9a9db7b3945f8e7b0286866d2cc3b61 Gerrit-PatchSet: 1 Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-Owner: Laszlo Gaal <laszlo.g...@cloudera.com> Gerrit-Reviewer: Alex Behm <alex.b...@cloudera.com> Gerrit-Reviewer: Laszlo Gaal <laszlo.g...@cloudera.com> Gerrit-Reviewer: Marcel Kornacker <mar...@cloudera.com> Gerrit-Reviewer: Tim Armstrong <tarmstr...@cloudera.com> Gerrit-HasComments: Yes
