Clouseau: Separate write folders for each instance

[poor-a]

Overview

The default Clouseau configuration in ./dev/run results in all Clouseau instances trying to write index files to the same folder. That creates a race condition. Observable symptom of the race condition is the following curl output:

$ curl -v -X GET --location 'http://admin:secret@localhost:25984/movies/_design/by-director-search/_search/by-director?query=director_3astring:*&include_docs=true'

Output:

{"error":"unknown_error","reason":"Lock obtain timed out: NativeFSLock@/Users/arturpoor/repo/couchdb/target/indexes/shards/00000000-7fffffff/movies.1782896092/c146b6fb754fa06bbbcbf78855ddb020/write.lock"}
* Connection #0 to host localhost left intact

Checklist

• This is my own work, I did not use AI, LLM's or similar technology
• Code is written and works correctly
• Changes are covered by tests
• Any new configurable parameters are documented in rel/overlay/etc/default.ini
• Documentation changes were made in the src/docs folder
• Documentation changes were backported (separated PR) to affected branches

[pgj]

I do not think that is needed. The index directories are configured ad hoc via overrides to the configuration by Java properties, i.e. by passing -Dclouseau.dir=<path>. Please note that dev/run script still does that and it is Clouseau 3.x that ignores that. So instead of touching dev/run we should fix this regression in the Clouseau source code itself.

[poor-a]

The index directories are configured ad hoc via overrides to the configuration by Java properties, i.e. by passing -Dclouseau.dir=

That is also a viable option. IMHO it's better to keep all configuration settings in one place (e.g. the clouseau.conf config file) for easier understanding. It's more difficult to follow if configuration is scattered across several files in the repo.

[poor-a]

Also the CouchDB database files are located under dev/lib/node{n} - it makes sense to keep the Clouseau index files there as well.

[rnewson]

Gabor's point aside for a moment, this path needs to use the ctx["devdir"] variable rather than assume 'dev/'

[rnewson]

I agree with gabor that the -Dclouseau.dir behaviour in clouseau should be restored.