journald/read: avoid piling up open files
If we take a long time to process log messages, and during that time
journal file rotation occurs, the journald client library will keep
those rotated files open until sd_journal_process() is called.
By periodically calling sd_journal_process() during the processing
loop we shrink the window of time a client instance has open file
descriptors for rotated (deleted) journal files.
This code is modelled after that of journalctl [1]; the above explanation
as well as the value of 1024 is taken from there.
[v2: fix CErr() argument]
[1] https://github.com/systemd/systemd/blob/dc16327c48d/src/journal/journalctl.c#L2676
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
(cherry picked from commit b73fb8fd5d521081c92b5c2cce334c21b2e0ff5f)
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Kir Kolyshkin authored on 2019/03/10 12:39:33Showing 1 changed files
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@@ -113,6 +113,7 @@ import ( |
| 113 | 113 |
"github.com/coreos/go-systemd/journal" |
| 114 | 114 |
"github.com/docker/docker/api/types/backend" |
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"github.com/docker/docker/daemon/logger" |
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+ "github.com/sirupsen/logrus" |
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) |
| 117 | 118 |
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func (s *journald) Close() error {
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| ... | ... |
@@ -205,6 +206,16 @@ drain: |
| 205 | 205 |
}: |
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shown++ |
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} |
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+ // Call sd_journal_process() periodically during the processing loop |
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+ // to close any opened file descriptors for rotated (deleted) journal files. |
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+ if shown%1024 == 0 {
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+ if ret := C.sd_journal_process(j); ret < 0 {
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+ // log a warning but ignore it for now |
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+ logrus.WithField("container", s.vars["CONTAINER_ID_FULL"]).
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+ WithField("error", CErr(ret)).
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+ Warn("journald: error processing journal")
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+ } |
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+ } |
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} |
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// If we're at the end of the journal, we're done (for now). |
| 210 | 220 |
if C.sd_journal_next(j) <= 0 {
|