If there are many of them, it probably means that MaxSpareThreads is set too small, or that MaxRequestsPerChild is non-zero and not large enough; see below for more information on both these directives. It is possible to see more child processes than this if some of them are gracefully stopping.
PROC(5) Linux Programmer’s Manual PROC(5) NAME top proc – process information pseudo-filesystem DESCRIPTION top.
It is usually much more effective to actively prevent backend systems from accepting more connections than they can reliably handle, performing throttling at the TCP level. When this is done at the client (HTTP Plugin) side, there is no cross-system or cross-process coordination which makes the limits ineffective.
Web server administrators will generally only become aware of this situation when they observe the CPU utilization approaching 100%. End users will generally not be aware that SSL session is not being reused unless the overhead of continually negotiating new sessions causes excessive delay in responses. The point at which this becomes noticeable will depend on the performance of the web server hardware, and whether or not a cryptographic accelerator is being used.
Installation and maintenance of crypto cards is relatively complex and usually results in a relatively small reduction in CPU usage. The preferred approach to improving SSL performance is to use software tuning to the greatest extent possible. We have observed many situations where the improvement is less than 10%.
At any given moment, a single user can require anywhere from zero to four independent TCP connections. The maximum number of simultaneous connections must be based on the busiest part of the day. This maximum number of simultaneous connections is only loosely related to the number of users accessing the site.
For IHS V8R0 and later, new ciphers and a new syntax for SSLCipherSpec are supported. This is a required change since new TLS protocols with a disjoint set of ciphers are supported. These same releases of IHS also favor strong ciphers, but also completely disable weak and export ciphers.
Find answers to commonly asked Linux questions. If you want to see the number of threads per.
FRCA cannot be used for serving content over HTTPS/SSL connections. The use of FRCA can dramatically reduce CPU utilization in some configurations. The Fast Response Cache Accelerator (FRCA, aka AFPA) is disabled in the current default configuration files because some common Windows extensions, such as Norton Antivirus, are not compatible with it. FRCA is a kernel resident micro HTTP server optimized for serving static, non-access protected files directly out of the file system.
Increasing ThreadsPerChild (and ThreadLimit) will reduce the number of total server processes needed, reducing the per-server memory overhead. Notably, this increases the per-process footprint which can be detrimental on 32-bit httpds. Search this document for ThreadsPerChild and consider all the warnings before changing it. However, there are a number of possible drawbacks to increasing ThreadsPerChild.
I intentionally did not focus on ‘pthread_exit()’ and the ‘sleep()’ function in this part as this part was intended to just give a small overview of how threads come alive. The two points that you brought into notice will be covered in the next part of the ongoing series of Linux threads. The subsequent parts will peel of the layers and will focus on deeper aspects including ‘pthread_exit()’ and why sleep() should not be used etc. @steve
Hi Steve, thanks for you valuable comments.
How can I manage this. I want to know the threads running for a particular process in Linux.