If queries have become slow, what tools can help troubleshoot?

To analyze slow queries in Java applications, the following tools can be used:

• Profilers: VisualVM, YourKit, JProfiler — help identify bottlenecks in code and determine where time is spent.
• Logging and tracing: enabling detailed logging (e.g., with SLF4J, Logback) and request tracing (e.g., Spring Boot Actuator, Sleuth).
• APM systems (Application Performance Monitoring): New Relic, AppDynamics, Datadog — provide performance metrics, request tracing, and slowdown analysis.
• JMX and JConsole: monitoring JVM status, collecting statistics on threads, memory, and garbage collection.
• Tools for analyzing SQL queries: if slowness is related to the database, check the slow query log, use EXPLAIN to analyze queries.

Example of using VisualVM for profiling:

# Launch VisualVM
visualvm

# Connect to a running Java process
# Start CPU profiling
# Analyze hot methods and execution time

Thus, a combination of profiling, logging, and monitoring will help identify the cause of slow query performance.