Catalina_ThreadPool_currentThreadCount: This metric represents the current number of threads in the thread pool managed by Apache Tomcat’s Catalina engine. It includes both active threads processing requests and idle threads waiting for new tasks.
Catalina_Servlet_errorCount: This metric tracks the total number of errors that have occurred in servlets within Apache Tomcat’s Catalina engine. It counts instances where servlets encountered exceptions or failed to handle requests successfully.
Catalina_Servlet_maxTime: This metric measures the maximum time taken by servlets to process requests within Apache Tomcat’s Catalina engine. It indicates the longest duration that any servlet has taken to handle a request.
Catalina_GlobalRequestProcessor_processingTime: This metric measures the total processing time of requests handled by the global request processor in Apache Tomcat’s Catalina engine.
Catalina_StringCache_accessCount: This metric tracks the total number of times the string cache has been accessed within Apache Tomcat’s Catalina engine. The string cache is used to store frequently accessed strings to optimize memory usage and improve performance by reducing the need for string object creation.
Catalina_Manager_activeSessions: This metric indicates the current number of active sessions managed by the Tomcat Manager. Active sessions represent client connections that are currently interacting with the server and haven’t timed out or been invalidated.
Catalina_Manager_expiredSessions: This metric tracks the total number of sessions that have expired and been removed from the Tomcat Manager. Session expiration occurs when a session’s timeout period elapses without any client activity.
Catalina_Manager_rejectedSessions: This metric indicates the total number of client connection requests that have been rejected by the Tomcat Manager due to capacity limits or other restrictions. Rejected sessions occur when the server cannot accommodate additional client connections beyond its configured limits.
Catalina_Manager_maxActiveSessions: This metric indicates the maximum number of active sessions that the Tomcat Manager can handle simultaneously. It represents the configured or default limit on the number of sessions that can be active at any given time.
Catalina_Manager_sessionMaxAliveTime: This metric shows how long sessions managed by Tomcat can stay active, in seconds, before they are automatically ended due to no activity.
Catalina_RequestProcessor_bytesSent: This metric measures the total number of bytes sent by the request processor in Apache Tomcat’s Catalina engine. It tracks the cumulative amount of data, in bytes, that has been successfully transmitted to clients in response to their requests
Tomcat Threads Panel
The “Tomcat Threads” panel in the Tomcat dashboard provides information about the current number of threads in the Tomcat server. This helps assess the server’s load and determine if the thread pool size is properly configured to efficiently handle incoming requests.
Total Errors Panel
The “Total Errors” panel in the Tomcat dashboard, aggregates the total count of servlet errors that have occurred on the specified Tomcat instance. This panel helps in tracking and monitoring the cumulative number of errors encountered by the servlets running on this Tomcat instance
Max time Panel
The “Max time” panel in the Tomcat dashboard tracks the longest response times of various servlets within the Tomcat server. Each servlet listed, including Captcha, Image, StartUpServlet, Default, JSP, and Spring, showcases the maximum duration taken to handle requests.
Average Processing Time Panel
The “Average Processing Time” panel in the Tomcat dashboard provides insights into the average time taken by requests processed by the Catalina GlobalRequestProcessor.It reflects the duration for handling incoming requests, indicating the server’s overall efficiency in responding to client requests.
Cache Hit / Total Panel The “Cache Hit / Total” panel in the Tomcat dashboard provides information about the efficiency of the string caching mechanism used by Tomcat. This tracks the total number of accesses made to the string cache, indicating how often strings are retrieved from the cache compared to how often they are fetched or computed anew.
Total Created Panel This panel tracks the cumulative number of sessions that have been created by Tomcat since it started running. Each session represents a unique interaction between a client and the Tomcat server.
Total Rejected Panel
This panel indicates the total number of session creation attempts that were rejected by Tomcat. Rejections can occur due to various reasons such as resource constraints, configuration limits, or security policies.
Total Expired Panel
This panel counts the total number of sessions that have expired and been removed by Tomcat. Sessions typically expire after a period of inactivity or when explicitly invalidated by the application.
Max Alive Panel
The “Max Alive” panel in the Tomcat dashboard, provides insights into the maximum duration that sessions remain active before they are automatically expired by Tomcat. This metric measures the longest period that any session has remained alive.
Sessions Panel
The “Sessions” panel in the Tomcat dashboard, provides insights into the configuration and management of active sessions within the Tomcat server environment. This metric typically captures details about the maximum number of concurrent sessions allowed or actively managed by Tomcat.
Bytes Sent /sec Panel
The “Bytes Sent /sec” panel in the Tomcat dashboard, provides insights into the rate of data transmission from the Tomcat server to clients over time. This metric captures the amount of data, measured in bytes, sent by Tomcat in response to client requests, helping to monitor network traffic and data throughput efficiency.