System ResourcesSystem Resources are basically the indicators about the performance of any application node at any given point of time. Users can refer to these important vital indicators to understand and track the node performance at any instant. These vital resources help us to review and analyze the performance of any node we are connected to at any time. System Resources can be found on stats.do page on the instance. Below are the steps. Goto Navigation Panel, All MenuType Stats.do and press Enter. This stats.do page contains various indicators like Servlet Memory, Servlet Statistics, Semaphores, Database Connection Pools, Scheduler Workers and few other configuration items. Below are the brief description about each of these indicators on the stats.do page and what they indicate on the performance side. Servlet Memory: ============= Servlet Memory section consists of few parts like the Maximum or Allocated Memory which shows the maximum allocated memory to the application node. The In Use memory shows current memory utilisation by the node and Free percentage shows the percentage availability of memory on the node at any given point of time. If this Free percentage goes below 10 and if you refresh the stats page and keep on seeing the available memory less, then this could be a possible situation of a node experiencing a memory contention and users connected to the node during the time might face slowness . Servlet Statistics: ================= Servlet statistics have details like the restart time which shows the last time when the node got restarted. It has few other parameters like the cache flushes, the errors count , logged in sessions and some other configuration items. Semaphores: ========== A semaphore is used on the platform to limit the number of transactions that can occur on a node at one time in order to protect resources on the node. When a user submits a request, it is routed through a semaphore pool where it basically joins a queue. If there is a free semaphore in that pool, then the request will grab it and process. When the transaction is complete, the semaphore is released and is free to process other requests that are in the queue. We have different types of semaphore pools like Default, AMB Send/Receive, API-INT and Presence. For example if we take Default semaphore Pool , it has few things like Available Semaphore Count which shows the number of semaphores available for the incoming requests. The Queue Depth shows the number of requests waiting in the queue t acquire the free semaphore. And the Queue Depth Limit shows maximum queue limit till which it will accept the requests. Database Connection Pools: ===================== Database Connection Pools are the pool of connections made by the application node to the database. Normally there is a throttling mechanisms which provide 32 database connections for each node concurrently. If Multiple connections get stuck or hung, then there might be performance degradation on the node. Scheduler Workers: =============== Scheduler Worker threads indicate the jobs running on the particular node at any given point of time. These can be used to check if there are any long running jobs on the node or track any job running status. Checking system resources for specific nodes: =============================== In order to check the performance indicators for specific nodes, we can goto sys_cluster_state.LIST from navigation panel. On this table we can get the node id for all the primary and standby application nodes. We can use these node ids for specific nodes to check the stats on the sys_cluster_node_stats table.