[MESOS-9418] Add support for the `Discard` blkio operation type.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.5.4, 1.6.2, 1.7.1, 1.8.0
• Component/s: containerization, test
• Assignee: James Peach
• Reporter: James Peach
• Created: 26/Nov/18 19:14
• Updated: 06/May/19 07:56
• Resolved: 27/Nov/18 17:56

Description

The CgroupsIsolatorTest.ROOT_CGROUPS_BlkioUsage test fails on Linux 4.19 kernels.

[jpeach@jpeach mesos]$ uname -r
4.19.3-300.fc29.x86_64
[jpeach@jpeach build]$ sudo env GLOG_v=1 ./src/mesos-tests --verbose --gtest_filter=CgroupsIsolatorTest.ROOT_CGROUPS_BlkioUsage
...
W1126 10:45:44.941278 30021 cgroups.cpp:895] Skipping resource statistic for container 8f67e5f9-ebf0-436c-a1d2-f30c69883a27 because: Failed to parse blkio value '8:0 Discard 0' from 'blkio.io_service_bytes': Invalid major:minor device number: 'Discard'
../../../src/tests/containerizer/cgroups_isolator_tests.cpp:1890: Failure
Value of: usage->has_blkio_statistics()
  Actual: false
Expected: true
../../../src/tests/containerizer/cgroups_isolator_tests.cpp:1891: Failure
Expected: (2) <= (usage->blkio_statistics().throttling_size()), actual: 2 vs 0
../../../src/tests/containerizer/cgroups_isolator_tests.cpp:1902: Failure
totalThrottling is NONE
mesos-tests: ../../../3rdparty/stout/include/stout/option.hpp:119: T &Option<mesos::CgroupInfo_Blkio_Throttling_Statistics>::get() & [T = mesos::CgroupInfo_Blkio_Throttling_Statistics]: Assertion `isSome()' failed.
...

The actual cgroup format is:

[jpeach@jpeach blkio]$ pwd
/sys/fs/cgroup/blkio
[jpeach@jpeach blkio]$ cat mesos_test_e9c8e0aa-3172-4d8d-b216-c8f5286a7efc/blkio.io_service_bytes
8:0 Read 0
8:0 Write 0
8:0 Sync 0
8:0 Async 0
8:0 Discard 0
8:0 Total 0
Total 0