Details
Blocker Description
An empty checkpoint file was created due to the following incident.
At 17:12:25, the master assigned a task to an agent:
I0123 17:12:25.000000 18618 master.cpp:11457] Adding task 5602 with resources cpus(allocated: *):0.1; mem(allocated: *):128 on agent aaf0a62f-a6eb-4c1d-80db-5fdd26fe8008-S4 at slave(1)@<agent_ip>:5051 (<agent_ip>) I0123 17:12:25.000000 18618 master.cpp:5017] Launching task 5602 of framework 6f9b0688-38f7-4b38-bb1c-421f55e486e5-0112 (Balloon Framework OOM) at scheduler-fbba22f7-ebbc-4864-8394-0aa558f8ffaa@<ip>:10015 with resources [...] on agent aaf0a62f-a6eb-4c1d-80db-5fdd26fe8008-S4 at slave(1)@<agent_ip>:5051 (<agent_ip>)
Meanwhile, the agent is being rebooted:
$ last reboot reboot system boot 3.10.0-693.11.6. Tue Jan 23 17:14 - 00:09 (06:55)
The agent log did not show any information about the task, possibly because there was no fsync before reboot:
I0123 17:12:09.000000 17237 http.cpp:851] Authorizing principal 'dcos_checks_agent' to GET the endpoint '/metrics/snapshot' -- Reboot -- I0123 17:15:40.000000 2689 logsink.cpp:89] Added FileSink for glog logs to: /var/log/mesos/mesos-agent.log
However, the agent was checkpointing the task before reboot:
$ sudo stat /var/lib/mesos/slave/meta/slaves/aaf0a62f-a6eb-4c1d-80db-5fdd26fe8008-S4/frameworks/6f9b0688-38f7-4b38-bb1c-421f55e486e5-0112/executors/5602/ File: ‘/var/lib/mesos/slave/meta/slaves/aaf0a62f-a6eb-4c1d-80db-5fdd26fe8008-S4/frameworks/6f9b0688-38f7-4b38-bb1c-421f55e486e5-0112/executors/5602/’ Size: 39 Blocks: 0 IO Block: 4096 directory Device: ca40h/51776d Inode: 67306254 Links: 3 Access: (0755/drwxr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root) Context: system_u:object_r:unlabeled_t:s0 Access: 2018-01-24 00:23:43.237322609 +0000 Modify: 2018-01-23 17:12:25.751463030 +0000 Change: 2018-01-23 17:12:25.751463030 +0000 Birth: -
And since there was no fsync before reboot, all checkpoints resulted in empty files:
$ sudo stat /var/lib/mesos/slave/meta/slaves/aaf0a62f-a6eb-4c1d-80db-5fdd26fe8008-S4/frameworks/6f9b0688-38f7-4b38-bb1c-421f55e486e5-0112/framework.info File: ‘/var/lib/mesos/slave/meta/slaves/aaf0a62f-a6eb-4c1d-80db-5fdd26fe8008-S4/frameworks/6f9b0688-38f7-4b38-bb1c-421f55e486e5-0112/framework.info’ Size: 0 Blocks: 0 IO Block: 4096 regular empty file Device: ca40h/51776d Inode: 33967500 Links: 1 Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/ root) Context: system_u:object_r:unlabeled_t:s0 Access: 2018-01-23 17:15:41.485506070 +0000 Modify: 2018-01-23 17:12:25.749463047 +0000 Change: 2018-01-23 17:12:25.749463047 +0000 Birth: - $ sudo stat /var/lib/mesos/slave/meta/slaves/aaf0a62f-a6eb-4c1d-80db-5fdd26fe8008-S4/frameworks/6f9b0688-38f7-4b38-bb1c-421f55e486e5-0112/framework.pid File: ‘/var/lib/mesos/slave/meta/slaves/aaf0a62f-a6eb-4c1d-80db-5fdd26fe8008-S4/frameworks/6f9b0688-38f7-4b38-bb1c-421f55e486e5-0112/framework.pid’ Size: 0 Blocks: 0 IO Block: 4096 regular empty file Device: ca40h/51776d Inode: 33967495 Links: 1 Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/ root) Context: system_u:object_r:unlabeled_t:s0 Access: 2018-01-23 23:00:42.190975780 +0000 Modify: 2018-01-23 17:12:25.749463047 +0000 Change: 2018-01-23 17:12:25.749463047 +0000 Birth: - $ sudo stat /var/lib/mesos/slave/meta/slaves/aaf0a62f-a6eb-4c1d-80db-5fdd26fe8008-S4/frameworks/6f9b0688-38f7-4b38-bb1c-421f55e486e5-0112/executors/5602/executor.info File: ‘/var/lib/mesos/slave/meta/slaves/aaf0a62f-a6eb-4c1d-80db-5fdd26fe8008-S4/frameworks/6f9b0688-38f7-4b38-bb1c-421f55e486e5-0112/executors/5602/executor.info’ Size: 0 Blocks: 0 IO Block: 4096 regular empty file Device: ca40h/51776d Inode: 67306255 Links: 1 Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/ root) Context: system_u:object_r:unlabeled_t:s0 Access: 2018-01-23 17:12:25.751463030 +0000 Modify: 2018-01-23 17:12:25.751463030 +0000 Change: 2018-01-23 17:12:25.751463030 +0000 Birth: -
So were forked.pid and task.info.
As a result, the agent failed to recover after reboot:
E0123 17:15:41.000000 2709 slave.cpp:6800] EXIT with status 1: Failed to perform recovery: Failed to recover framework 6f9b0688-38f7-4b38-bb1c-421f55e486e5-0112: Failed to read framework info from '/var/lib/mesos/slave/meta/slaves/aaf0a62f-a6eb-4c1d-80db-5fdd26fe8008-S4/frameworks/6f9b0688-38f7-4b38-bb1c-421f55e486e5-0112/framework.info': Found an empty file
The error came from https://github.com/apache/mesos/blob/a892a2e80255291e6cd5cb3b0e90b9a029989c99/3rdparty/stout/include/stout/protobuf.hpp#L367.
This is related to a recent change of the checkpoint recovery logic: we used to ignore empty checkpoint files before, but now it return errors on empty checkpoint files.