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https://issues.apache.org/jira/browse/TS-4834?focusedWorklogId=28749&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-28749
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ASF GitHub Bot logged work on TS-4834:
--------------------------------------
Author: ASF GitHub Bot
Created on: 11/Sep/16 20:42
Start Date: 11/Sep/16 20:42
Worklog Time Spent: 10m
Work Description: Github user SolidWallOfCode commented on a diff in the
pull request:
https://github.com/apache/trafficserver/pull/996#discussion_r78302115
--- Diff: iocore/cache/Cache.cc ---
@@ -2070,6 +2070,16 @@ AIO_Callback_handler::handle_disk_failure(int /*
event ATS_UNUSED */, void *data
for (; disk_no < gndisks; disk_no++) {
CacheDisk *d = gdisks[disk_no];
+ /* find the Vol instance needed for updating per-volume stats by
CACHE_INCREMENT_DYN_STAT */
+ Vol *vol;
--- End diff --
If there are multiple volumes for the same physical disk / file descriptor,
does this just find the first one?
Issue Time Tracking
-------------------
Worklog Id: (was: 28749)
Time Spent: 50m (was: 40m)
> Expose bad disk and disk access failures
> ----------------------------------------
>
> Key: TS-4834
> URL: https://issues.apache.org/jira/browse/TS-4834
> Project: Traffic Server
> Issue Type: Improvement
> Components: Cache, Metrics
> Reporter: Gancho Tenev
> Assignee: Gancho Tenev
> Fix For: 7.0.0
>
> Time Spent: 50m
> Remaining Estimate: 0h
>
> We would like to monitor low-level disk access failures and disks marked by
> ATS as bad.
> I have a patch that exposes that information through
> {code}
> proxy.process.cache.disk_error_count 10
> proxy.process.cache.disk_bad_count 5
> {code}
> and the following tests/shows how it would work...
> Start ATS with 2 disks and tail {{diags.log}}
> {code}
> $ cat etc/trafficserver/storage.config
> /dev/sdb
> /dev/sdc
> $ tail -f var/log/trafficserver/diags.log
> [Sep 8 12:18:48.149] Server {0x2b5f43db54c0} NOTE: traffic server running
> [Sep 8 12:18:48.198] Server {0x2b5f44654700} NOTE: cache enabled
> {code}
> Check related metrics and observe all 0s
> {code}
> $ ./bin/traffic_ctl metric match "proxy.process.cache*.disk.*"
> "proxy.process.cache.*(read|write).failure"
> "proxy.process.http.cache_(read|write)_errors"
> proxy.process.cache.disk_error_count 0
> proxy.process.cache.disk_bad_count 0
> proxy.process.cache.read.failure 0
> proxy.process.cache.write.failure 0
> proxy.process.cache.volume_0.read.failure 0
> proxy.process.cache.volume_0.write.failure 0
> proxy.process.http.cache_write_errors 0
> proxy.process.http.cache_read_errors 0
> {code}
> Now using your favorite hard disk failure injection tool inject 10 failures,
> by setting both disks used by this setup {{/dev/sdb}} and {{/dev/sdc}} to
> fail all reads. And shoot 5 requests causing 10 failed reads.
> {code}
> $ for i in 1 2 3 4 5; do curl -x 127.0.0.1:80 http://example.com/1 -o
> /dev/null -s; done
> $ tail -f var/log/trafficserver/diags.log
> [Sep 8 12:19:09.758] Server {0x2aaab4302700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:19:09.759] Server {0x2aaac0100700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:19:09.764] Server {0x2b5f43db54c0} WARNING: Error accessing Disk
> /dev/sdb [1/10]
> [Sep 8 12:19:09.769] Server {0x2b5f44654700} WARNING: Error accessing Disk
> /dev/sdb [2/10]
> [Sep 8 12:19:09.785] Server {0x2aaac0100700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:19:09.786] Server {0x2aaab4302700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:19:09.791] Server {0x2b5f44654700} WARNING: Error accessing Disk
> /dev/sdb [3/10]
> [Sep 8 12:19:09.796] Server {0x2b5f43db54c0} WARNING: Error accessing Disk
> /dev/sdb [4/10]
> [Sep 8 12:19:09.812] Server {0x2aaab4100700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:19:09.813] Server {0x2aaacc100700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:19:09.817] Server {0x2b5f43db54c0} WARNING: Error accessing Disk
> /dev/sdb [5/10]
> [Sep 8 12:19:09.823] Server {0x2b5f44654700} WARNING: Error accessing Disk
> /dev/sdb [6/10]
> [Sep 8 12:19:09.843] Server {0x2aaacc302700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:19:09.844] Server {0x2aaad8100700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:19:09.847] Server {0x2b5f44654700} WARNING: Error accessing Disk
> /dev/sdb [7/10]
> [Sep 8 12:19:09.854] Server {0x2b5f43db54c0} WARNING: Error accessing Disk
> /dev/sdb [8/10]
> [Sep 8 12:19:09.874] Server {0x2aaacc302700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:19:09.875] Server {0x2aaad8100700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:19:09.880] Server {0x2b5f43db54c0} WARNING: Error accessing Disk
> /dev/sdb [9/10]
> [Sep 8 12:19:09.887] Server {0x2b5f44654700} WARNING: too many errors
> accessing disk /dev/sdb [10/10]: declaring disk bad
> {code}
> We see 5 read failures which triggered 10 actually disk reads and marked the
> failing disk as a bad disk.
> {code}
> $ ./bin/traffic_ctl metric match "proxy.process.cache*.disk.*"
> "proxy.process.cache.*(read|write).failure"
> "proxy.process.http.cache_(read|write)_errors"
> proxy.process.cache.disk_error_count 10
> proxy.process.cache.disk_bad_count 1
> proxy.process.cache.read.failure 5
> proxy.process.cache.write.failure 5
> proxy.process.cache.volume_0.read.failure 5
> proxy.process.cache.volume_0.write.failure 5
> proxy.process.http.cache_write_errors 0
> proxy.process.http.cache_read_errors 0
> {code}
> Now shoot 5 requests causing 10 failed reads.
> {code}
> $ for i in 1 2 3 4 5; do curl -x 127.0.0.1:80 http://example.com/1 -o
> /dev/null -s; done
> $ tail -f var/log/trafficserver/diags.log
> [Sep 8 12:26:02.874] Server {0x2aaae4100700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:26:02.875] Server {0x2aaaf0302700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:26:02.876] Server {0x2b5f44654700} WARNING: Error accessing Disk
> /dev/sdc [1/10]
> [Sep 8 12:26:02.885] Server {0x2b5f43db54c0} WARNING: Error accessing Disk
> /dev/sdc [2/10]
> [Sep 8 12:26:02.902] Server {0x2aaaf0302700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:26:02.902] Server {0x2aaae4100700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:26:02.907] Server {0x2b5f43db54c0} WARNING: Error accessing Disk
> /dev/sdc [3/10]
> [Sep 8 12:26:02.914] Server {0x2b5f44654700} WARNING: Error accessing Disk
> /dev/sdc [4/10]
> [Sep 8 12:26:02.936] Server {0x2aaafc100700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:26:02.936] Server {0x2aab08100700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:26:02.940] Server {0x2b5f44654700} WARNING: Error accessing Disk
> /dev/sdc [5/10]
> [Sep 8 12:26:02.946] Server {0x2b5f43db54c0} WARNING: Error accessing Disk
> /dev/sdc [6/10]
> [Sep 8 12:26:02.971] Server {0x2aab08100700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:26:02.971] Server {0x2aaafc100700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:26:02.976] Server {0x2b5f43db54c0} WARNING: Error accessing Disk
> /dev/sdc [7/10]
> [Sep 8 12:26:02.982] Server {0x2b5f44654700} WARNING: Error accessing Disk
> /dev/sdc [8/10]
> [Sep 8 12:26:03.002] Server {0x2aaafc100700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:26:03.002] Server {0x2aab08100700} WARNING: cache disk operation
> failed READ -1 0
> [Sep 8 12:26:03.006] Server {0x2b5f44654700} WARNING: Error accessing Disk
> /dev/sdc [9/10]
> [Sep 8 12:26:03.012] Server {0x2b5f43db54c0} WARNING: too many errors
> accessing disk /dev/sdc [10/10]: declaring disk bad
> {code}
> We see 5 more read failures which triggered 10 more actual failed disk reads
> and marked the second disk as bad.
> {code}
> $ ./bin/traffic_ctl metric match "proxy.process.cache*.disk.*"
> "proxy.process.cache.*(read|write).failure"
> "proxy.process.http.cache_(read|write)_errors"
> proxy.process.cache.disk_error_count 20
> proxy.process.cache.disk_bad_count 2
> proxy.process.cache.read.failure 10
> proxy.process.cache.write.failure 10
> proxy.process.cache.volume_0.read.failure 10
> proxy.process.cache.volume_0.write.failure 10
> proxy.process.http.cache_write_errors 0
> proxy.process.http.cache_read_errors 0
> {code}
> After marking all the (2) disks as bad finally ATS disabled the cache and
> started going to origin on every requests.
> {code}
> $ tail -f var/log/trafficserver/diags.log
> [Sep 8 12:26:03.012] Server {0x2b5f43db54c0} WARNING: All storage devices
> offline, cache disabled
> {code}
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