Kbase 21989: More Thread Information for AdminServer on Linux
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
23/04/2002 |
|
SUMMARY:
This Solution summarizes what factors can contribute to high thread count, thus high process count, for Progress 9.1C AdminServer on Linux.
EXPLANATION:
In Java 2 Release 1.3 for Linux, the Hotspot virtual machine uses system threads to implement Java threads. Because Linux threads are implemented as a cloned process, each Java thread shows up in the process table if you run the ps command. This is normal behavior on Linux.
For the Progress AdminServer product, depending on what you have installed, the thread count in AdminServer can vary.
In the following example, you see the most basic configuration; only the database plugin is installed. Here is a thread dump from jdb.
> threads
Group system:
(java.lang.ref.Reference$ReferenceHandler)0x3 Reference Handle
(java.lang.ref.Finalizer$FinalizerThread)0x4 Finalizer
(java.lang.Thread)0x5 Signal Dispatcher
(java.lang.Thread)0x6 CompileThread0
(java.lang.Thread)0x7 RMI TCP Accept-1
(java.lang.Thread)0x8 RMI Reaper
(sun.misc.GC$Daemon)0x9 GC Daemon
(java.lang.Thread)0xa RMI TCP Accept-2
(java.lang.Thread)0xb RMIRenewClean-[
(java.lang.Thread)0xc RMILeaseChecker
Group main:
(java.lang.Thread)0x1 main
(com.Progress.common.networkevents.EventBroker$Router)0x13 Event
input hand
(com.progress.common.comsock.ServerComSock)0x14 ServerSocket Ut
(com.progress.juniper.admin.ConfigListener)0x15 Juniper Plug-in
(com.progress.common.networkevents.Client$Messenger)0x16 Thread-4
(java.lang.Thread)0x17 AdminServer
Each plugin is in a thread. In this case, thread 0x15 is the database plugin. Depending on what the plugin does, there are more threads
created by the plugin -- for example, thread 0x14 is the thread started by the database plugin to listen for database connections.
The event broker for the AdminServer launches thread 0x13 and 0x16.
The AdminServer itself is another thread 0x17.
Group system contains the system threads, garbage collector, RMI
communication threads, etc.
With this simplest configuration, there are 16 threads already in the
jvm. If Fathom is installed on top of it, the thread count for AdminServer will jump to 30+. The additional threads are created in the Fathom plugin.
References to Written Documentation:
http://developer.Java.sun.com/developer/technicalArticles/Programming/linux/