How do I inspect MySQL connections and long-running work without killing queries?

1. Read the connection count

Compare the value with a normal baseline for this application and time of day. An isolated count does not establish a leak or capacity fault.

SHOW GLOBAL STATUS LIKE 'Threads_connected';

Reads the current connection-count status variable.

2. Read a bounded metadata sample

The query omits statement text to reduce unnecessary exposure of customer data or credentials embedded in SQL. Sorting by duration highlights work or idle states that have persisted longest.

SELECT ID, USER, HOST, DB, COMMAND, TIME, STATE
FROM performance_schema.processlist
ORDER BY TIME DESC
LIMIT 20;

Lists up to twenty process records available to the authorised account; visibility depends on privileges.

3. Correlate with the application

Distinguish sleeping pooled connections, long active statements and waiting states. Check whether the application closes connections and whether a database lock or downstream dependency explains the symptom. Preserve a small time-stamped sample before deciding on a targeted intervention.