docker_logger: reorder imports to save memory #14875
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Nomad runs one logmon process and also one docker_logger process for each running allocation. A naive look at memory usage shows 10-30 MB of RSS, but a closer look shows that most of this memory (ex. all but ~2MB for logmon) is shared (`Shared_Clean` in Linux pmap). But a heap dump of docker_logger shows that it currently has an extra ~2500 KiB of heap (anonymously-mapped unshared memory) used for init blocks coming from the agent code (ex. mostly regexes from go-version, structs, and the Consul SDK). The packages for running logmon, docker_logger, and executor have an init block that parses `os.Args` to drop into their own logic, which prevents them from loading all the rest of the agent code and saves on memory, so this was unexpected. It looks like we accidentally reordered the imports in main to undo some of the work originally done in 404d2d4. This changeset restores the ordering. A follow-up heap dump shows this saves ~2MB of unshared RSS per docker_logger process.
tgross
force-pushed
the
docker_logger_memory
branch
from
bd74632 to
4bc4c93
Compare
tgross
added
backport/1.4.x
This was referenced Oct 11, 2022
tgross
added a commit
that referenced
this pull request
Oct 11, 2022
Nomad runs one logmon process and also one docker_logger process for each running allocation. A naive look at memory usage shows 10-30 MB of RSS, but a closer look shows that most of this memory (ex. all but ~2MB for logmon) is shared (`Shared_Clean` in Linux pmap). But a heap dump of docker_logger shows that it currently has an extra ~2500 KiB of heap (anonymously-mapped unshared memory) used for init blocks coming from the agent code (ex. mostly regexes from go-version, structs, and the Consul SDK). The packages for running logmon, docker_logger, and executor have an init block that parses `os.Args` to drop into their own logic, which prevents them from loading all the rest of the agent code and saves on memory, so this was unexpected. It looks like we accidentally reordered the imports in main to undo some of the work originally done in 404d2d4. This changeset restores the ordering. A follow-up heap dump shows this saves ~2MB of unshared RSS per docker_logger process.
tgross
added a commit
that referenced
this pull request
Oct 11, 2022
Nomad runs one logmon process and also one docker_logger process for each running allocation. A naive look at memory usage shows 10-30 MB of RSS, but a closer look shows that most of this memory (ex. all but ~2MB for logmon) is shared (`Shared_Clean` in Linux pmap). But a heap dump of docker_logger shows that it currently has an extra ~2500 KiB of heap (anonymously-mapped unshared memory) used for init blocks coming from the agent code (ex. mostly regexes from go-version, structs, and the Consul SDK). The packages for running logmon, docker_logger, and executor have an init block that parses `os.Args` to drop into their own logic, which prevents them from loading all the rest of the agent code and saves on memory, so this was unexpected. It looks like we accidentally reordered the imports in main to undo some of the work originally done in 404d2d4. This changeset restores the ordering. A follow-up heap dump shows this saves ~2MB of unshared RSS per docker_logger process. Co-authored-by: Tim Gross <[email protected]>
|
I'm going to lock this pull request because it has been closed for 120 days ⏳. This helps our maintainers find and focus on the active contributions. |
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Nomad runs one logmon process and also one docker_logger process for each running allocation. A naive look at memory usage shows 10-30 MB of RSS, but a closer look shows that most of this memory (ex. all but ~2MB for logmon) is shared (
Shared_Cleanin Linux pmap).But a heap dump of docker_logger shows that it currently has an extra ~2500 KiB of heap (anonymously-mapped unshared memory) used for init blocks coming from the agent code (ex. mostly regexes from go-version, structs, and the Consul SDK). The packages for running logmon, docker_logger, and executor have an init block that parses
os.Argsto drop into their own logic, which prevents them from loading all the rest of the agent code and saves on memory, so this was unexpected.It looks like we accidentally reordered the imports in main to undo some of the work originally done in 404d2d4. This changeset restores the ordering. A follow-up heap dump shows this saves ~2MB of unshared RSS per docker_logger process.