@Rocky From the documentation certain configurations are set in the

fe.conf

or

cn.conf

but it seems that certain configs like

enable_profile_log

are only mentioned in the

SET enable_profile_log

context (from runtime) and adding

enable_profile_log=true

to either/both my

fe.conf

or

cn.conf

files is not respected. How can I have this persistently set at startup?

In StarRocks, there are two distinct types of configurations, and the method for making them persistent depends on which type they belong to. Based on your description, you are likely encountering System Variables, which behave differently from Configuration Items. 1. System Variables (Session/Global) Variables like

enable_profile

(and potentially

enable_profile_log

depending on your version) are System Variables. * Why

fe.conf

doesn't work: These variables are managed via the SQL interface and stored in the FE's metadata (BDBJE), not in the configuration files. Any entries for these in

fe.conf

will be ignored. * How to persist: To set these persistently across cluster restarts and for all new sessions, you must use the

SET GLOBAL

command:

sql
    SET GLOBAL enable_profile = true;

Once set as

GLOBAL

, the value is written to the edit logs and will remain active even after a cluster restart. 2. FE/BE Configuration Items Parameters listed in the FE Configuration or BE Configuration documentation (like

sys_log_level

or

enable_collect_query_detail_info

) are true configuration items. * How to persist: These are set in

fe.conf

or

cn.conf

. * Runtime change: Many of these are "mutable," meaning you can change them without a restart using the

ADMIN

command:

sql
    ADMIN SET FRONTEND CONFIG ("enable_collect_query_detail_info" = "true");

Specifics for

enable_profile_log

The variable

enable_profile_log

was introduced in newer versions (v3.1+) specifically to control the

fe.profile.log

(a JSON-formatted log file for query analysis). * If you want to enable the Profile Web UI/Metadata collection (the most common request), use:

sql
    SET GLOBAL enable_profile = true;

* If you specifically want to enable the JSON profile log files (

fe.profile.log

) and find that

fe.conf

isn't picking it up, try setting it via the admin interface to verify if your version supports it as a mutable config:

sql
    ADMIN SET FRONTEND CONFIG ("enable_profile_log" = "true");

Summary Tip: If a setting is changed via

SET

, use

SET GLOBAL

to persist it. If it is changed via

ADMIN SET CONFIG

or mentioned as an FE/BE parameter, use `fe.conf`/`be.conf`. References • sql-reference/System_variable.md • administration/management/FE_configuration.md • administration/management/logs.md • best_practices/query_tuning/query_profile_overview.md • faq/Others.md • unloading/Spark_connector.md

add

enable_profile_log = true

in your fe.conf (all FEs) and restart the FEs. This will change the value