The docs here incorrectly state that it is okay for a heap dump file to
exist when heap dump path is configured to a fixed filename. This is
incorrect, the JVM will fail to write the heap dump if a heap dump file
already exists at the specified location (see the DumpWriter constructor
DumpWriter::DumpWriter(const char* path) in the JVM source).
On some Linux distributions tmpfiles.d cleans files and
directories under /tmp if they haven't been accessed for
10 days.
This can cause problems for ML as ML is currently the only
component that uses the temp directory more than a few
seconds after startup. If you didn't open an ML job for
10 days and then tried to open one then the temp directory
would have been deleted.
This commit prevents the problem occurring in the case of
Elasticsearch being managed by systemd, as systemd private
temp directories are not subject to periodic cleanup (by
default).
Additionally there are now some docs to warn people about
the risk and suggest a manual mitigation for .tar.gz users.
This is a follow up to a previous change which set the error file path
for the package distributions. The observation here is that we always
set the working directory of Elasticsearch to the root of the
installation (i.e., Elasticsearch home). Therefore, we can specify the
error file path relative to this directory and default it to the logs
directory, similar to the package distributions.
This is a follow up to a previous change which set the heap dump path
for the package distributions. The observation here is that we always
set the working directory of Elasticsearch to to the root of
installation (i.e., Elasticsearch home). Therefore, we can specify the
heap dump path relative to this directory and default it to the data
directory, similar to the package distributions.
This commit reorganizes some of the content in the configuring
Elasticsearch section of the docs. The changes are:
- move JVM options out of system configuration into configuring
Elasticsearch
- move JVM options to its own page of the docs
- move configuring the heap to important Elasticsearch settings
- move configuring the heap to its own page of the docs
- move all important settings to individual pages in the docs
- remove bootstrap.memory_lock from important settings, this is covered
in the swap section of system configuration
Relates #27755