[kudu-CR] KUDU-2135: persist disk states

["Andrew Wong (Code Review)" <ge...@cloudera.org>]

Hello Kudu Jenkins,

I'd like you to reexamine a change.  Please visit

    http://gerrit.cloudera.org:8080/7270

to look at the new patch set (#27).

Change subject: KUDU-2135: persist disk states
......................................................................

KUDU-2135: persist disk states

This patch adds a new version of the path set so failed disks are not
used when a server is run. A previously failed disk may continue to
produce IOErrors after restart, but we may still like to start the
server without the disk.

To accomplish this, disk states, path names, and a timestamp are added
to the path set. If any disks are failed when opening the initial FS
layout, an 'unhealthy' instance with no path set metadata will be
created instead of failing the startup process.

CheckIntegrity() is updated to accomodate this. Rather than comparing
all instances against an agreed-upon set of UUIDs, the single path set
with the largest timestamp is used as the main one to compare against
(if only old path sets are available, the first healthy one is used). If
no instances are healthy, CheckIntegrity() will fail, as all disks are
failed.

Testing is done in a new iteration of CheckIntegrity(). Further testing
is done in data_dirs-test, fs_manager-test, and log_block_manager-test
to ensure the FS layout can be loaded with a failed directory.

Some notes:
- Disk failures during FS layout creation are not tolerated. In these
  cases, there is presumably no data on the server anyway, so operators
  should easily be able to fix their cluster.
- If there are any unhealthy instances when upgrading the path sets (i.e.
  adding disk states, paths, timestamp), a complete mapping of UUIDs to
  paths will not be available, and CheckIntegrity() will fail.
- The main path set's disk states are updated to reflect the failure of
  the instances. Since data on a failed disk is not used, disks
  that are successfully read from but are already marked FAILED by the
  main path set are not marked HEALTHY.
- In the case of a server restart where all healthy disks fail to start
  up and some known failed disks start working again, the server will
  successfully start up with the bad disks

This patch is a part of a series of patches to handle disk failures. To
see how this fits, see 2.6 in:
https://docs.google.com/document/d/1zZk-vb_ETKUuePcZ9ZqoSK2oPvAAaEV1sjDXes8Pxgk/edit?usp=sharing

Change-Id: Ifddf0817fe1a82044077f5544c400c88de20769f
---
M src/kudu/fs/block_manager_util-test.cc
M src/kudu/fs/block_manager_util.cc
M src/kudu/fs/block_manager_util.h
M src/kudu/fs/data_dirs-test.cc
M src/kudu/fs/data_dirs.cc
M src/kudu/fs/data_dirs.h
M src/kudu/fs/fs.proto
M src/kudu/fs/log_block_manager.cc
8 files changed, 655 insertions(+), 150 deletions(-)


  git pull ssh://gerrit.cloudera.org:29418/kudu refs/changes/70/7270/27
-- 
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Gerrit-MessageType: newpatchset
Gerrit-Change-Id: Ifddf0817fe1a82044077f5544c400c88de20769f
Gerrit-PatchSet: 27
Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-Owner: Andrew Wong <aw...@cloudera.com>
Gerrit-Reviewer: Adar Dembo <ad...@cloudera.com>
Gerrit-Reviewer: Alexey Serbin <as...@cloudera.com>
Gerrit-Reviewer: Andrew Wong <aw...@cloudera.com>
Gerrit-Reviewer: Kudu Jenkins
Gerrit-Reviewer: Tidy Bot
Gerrit-Reviewer: Todd Lipcon <to...@apache.org>