[Progress Communities] [Progress OpenEdge ABL] Forum Post: Question about thread and memory resources consumed by "classic" appserver

[dbeavon]

Am I reading this right? The "statefree" appserver ("classic") consumes a thread for every remote connection, even when idle?! Glance 11.00.044 09:13:04 abc ia64 Current Avg High -------------------------------------------------------------------------------- CPU Util S SU U | 54% 43% 64% Disk Util F F | 8% 7% 77% Mem Util S SU UFF | 59% 59% 59% Networkil U URR | 62% 61% 62% -------------------------------------------------------------------------------- PROCESS LIST Users= 763 User CPU % Thrd Disk Memory Block Process Name PID Name (1600% max) Cnt IOrate RSS/VSS On -------------------------------------------------------------------------------- java 12345 root 5.4 901 0.0 828.6mb 3.49gb SLEEP See above there are 901 threads sleeping. This is on HP-UX. There is also significant memory usage. Memory seems to grow by 1-2 MB per connected client. Memory use is high, although not all the memory is resident at once (in RSS). Note that "statefree" client connections are typically long-running connections from an application that last the life of the client process. They don't disconnect until the user closes out of their applications. You can see the list of client connections with the asbman "-listclients" option. The clients aren't supposed to consume actual agent resources until they run a method. I was aware that each connected client would consume some broker memory (swapped to disk most of the time) but I never imagined a dedicated OS thread for each one! Even if it is sleeping most of the time, this cannot be a good use of resources! Let me know if I'm reading this wrong. I have been dabbling in "PASOE" and cannot imagine tomcat does anything like this (create a thread for every user who has an HTTP session). We've been getting "out-of-memory" java errors in our appserver brokers and it caused me to start investigating. We allow those java broker processes a max heap of 2000mb (-Xmx parameter). But even that amount of memory seems to be insufficient now after the "-listclients" gets above 1000 or so. I think we are going to be forced to double the -Xmx. It seems like "classic" appserver is wasteful of both OS threads and heap memory.

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