ElasticSearch Inline script compilation circuit breaker triggered on static script code

[Anver_S]

Using java rest api I submit bulk update requests with painless script

for (entry in params.entrySet()) {ctx._source[entry.getKey()] = entry.getValue();}

Occasionally I get dynamic compilation circuit breaker triggering on such updates.

Considering it is the only script we use I fail to understand why it would not compile once and get cached.

I am on rather old version of ES 7.2.0

[Anver_S]

I've changed the script to be stored in hopes it would be compiled once. But even stored script fails with dynamic compilation circuit breaker exception.

Elasticsearch exception [type=illegal_argument_exception, reason=failed to execute script]","caused_by":{"type":"exception","reason":"Elasticsearch excepti
on [type=general_script_exception, reason=Failed to compile stored script [replace_field_values] using lang [painless]]","caused_by":{"type":"exception","reason":"Elasticsearch exception [type=circuit_breaking_exception, reason=[script] Too many dynamic script compilations
within, max: [75/5m]; please use indexed, or scripts with parameters instead; this limit can be changed by the [script.max_compilations_rate] setting]","durability":"TRANSIENT"}}},"status":400}]

[Anver_S]

Apparently well behaved stored scripts can suffer from being evicted from cache and requiring compilation by other not so well behaved scripts. I did hope that stored scripts would be isolated in that regard but no such luck.

My service is using stored scripts and they were evicted by dynamically generated scripts from a different service on shared ElasticSearch instance. Cache limits per client would do the trick too. Oh well.

[Anver_S]

I assume cache churn is caused by using simple LRUCache - I wonder if Window TinyLFU (W-TinyLFU) eviction policy would give you a better result - well behaved scripts will not be affected by poorly designed dynamic scripts.
Solr has already switched to use GitHub - ben-manes/caffeine: A high performance caching library for Java as default recommended cache due to better caching stats