Re: mod_jk performance optimization

[M. Serrano]

Thanx for your reply, for it really helped.
I used jk from 3.3 and the previous error which appeard at mod_jk.log is 
gone. :-)
But...(there's always a but) another error appears when I request several 
servlet tasks simultaneously. In mod_jk.log:

[jk_ajp13_worker.c (381)]: Error ajp13_process_callback - write failed

I've also checked tomcat.log and the following error appears:

Ctx( /WebApplication ): Exception in: R( /WebApplication + 
/servlet/ServletObj + null) - java.lang.OutOfMemoryError
no stack trace available

After this the system is slower than ever. I tried to restart Tomcat but the 
system continues to be very...very slow.

I'd appreciate if some clues about this problem could be thrown
at me :-)

Thanx.
Serrano.

From: [EMAIL PROTECTED]
Reply-To: Tomcat Users List [EMAIL PROTECTED]
To: Tomcat Users List [EMAIL PROTECTED]
Subject: Re: mod_jk performance optimization
Date: Thu, 2 May 2002 10:04:13 -0700 (PDT)

On Thu, 2 May 2002, M. Serrano wrote:

  Hi.
 
  I've got installed in my box Linux, Apache 1.3.19, JDK 1.3.1 and TC 
3.3.1
  working with ajp13. The following error appeard in my mod_jk.log after a 
bit
  of continuous utilisation:
 
  [jk_ajp13_worker.c (203)]: connection_tcp_get_message: Error -
  jk_tcp_socket_recvfull failed
  [jk_ajp13_worker.c (621)]: Error reading request

From the line numbers, you may use an older version of jk, try updating
from CVS head first ( the bug may be already fixed ) ( you can use either
the 'frozen' jk from 3.3 or j-t-c ).

The error message means from some reasons tomcat didn't sent back any
content - so you may need to look in tomcat's lots as well.

( the 'reading request' means the request from tomcat to jk to send a
chunk of data )

Costin

 
  After analysing the server's config files and reading some threads, I
  concluded that the problem might be resolved through a bit of extra
  re-configuration. Although the problem appearence was delayed, it still
  existed.
 
  I wonder if anyone out there could help me with this subject. I'm 
sending in
  attach some lines of httpd.conf, server.xml and mod_jk.conf
 
  Thanx a lot for your time.
  Serrano.
 
  ##
  ## httpd.conf -- Apache HTTP server configuration file
  ##
 
  #
  # Timeout: The number of seconds before receives and sends time out.
  #
  Timeout 300
 
  #
  # KeepAlive: Whether or not to allow persistent connections (more than
  # one request per connection). Set to Off to deactivate.
  #
  KeepAlive On
 
  #
  # MaxKeepAliveRequests: The maximum number of requests to allow
  # during a persistent connection. Set to 0 to allow an unlimited amount.
  # We recommend you leave this number high, for maximum performance.
  #
  MaxKeepAliveRequests 100
 
  #
  # KeepAliveTimeout: Number of seconds to wait for the next request from 
the
  # same client on the same connection.
  #
  KeepAliveTimeout 15
 
  #
  # Server-pool size regulation.  Rather than making you guess how many
  # server processes you need, Apache dynamically adapts to the load it
  # sees --- that is, it tries to maintain enough server processes to
  # handle the current load, plus a few spare servers to handle transient
  # load spikes (e.g., multiple simultaneous requests from a single
  # Netscape browser).
  #
  # It does this by periodically checking how many servers are waiting
  # for a request.  If there are fewer than MinSpareServers, it creates
  # a new spare.  If there are more than MaxSpareServers, some of the
  # spares die off.  The default values are probably OK for most sites.
  #
  MinSpareServers 5
  MaxSpareServers 10
 
  #
  # Number of servers to start initially --- should be a reasonable 
ballpark
  # figure.
  #
  StartServers 8
 
  #
  # Limit on total number of servers running, i.e., limit on the number
  # of clients who can simultaneously connect --- if this limit is ever
  # reached, clients will be LOCKED OUT, so it should NOT BE SET TOO LOW.
  # It is intended mainly as a brake to keep a runaway server from taking
  # the system with it as it spirals down...
  #
  MaxClients 150
 
  #
  # MaxRequestsPerChild: the number of requests each child process is
  # allowed to process before the child dies.  The child will exit so
  # as to avoid problems after prolonged use when Apache (and maybe the
  # libraries it uses) leak memory or other resources.  On most systems, 
this
  # isn't really needed, but a few (such as Solaris) do have notable leaks
  # in the libraries. For these platforms, set to something like 1
  # or so; a setting of 0 means unlimited.
  #
  # NOTE: This value does not include keepalive requests after the initial
  #   request per connection. For example, if a child process handles
  #   an initial request and 10 subsequent keptalive requests, it
  #   would only count as 1 request towards this limit.
  #
  MaxRequestsPerChild 200
 
  #
  # DocumentRoot: The directory out of which you will serve your
  # documents. By default, all requests are taken from

mod_jk performance optimization

[M. Serrano]

Hi.

I've got installed in my box Linux, Apache 1.3.19, JDK 1.3.1 and TC 3.3.1 
working with ajp13. The following error appeard in my mod_jk.log after a bit 
of continuous utilisation:

[jk_ajp13_worker.c (203)]: connection_tcp_get_message: Error - 
jk_tcp_socket_recvfull failed
[jk_ajp13_worker.c (621)]: Error reading request

After analysing the server's config files and reading some threads, I 
concluded that the problem might be resolved through a bit of extra 
re-configuration. Although the problem appearence was delayed, it still 
existed.

I wonder if anyone out there could help me with this subject. I'm sending in 
attach some lines of httpd.conf, server.xml and mod_jk.conf

Thanx a lot for your time.
Serrano.

##
## httpd.conf -- Apache HTTP server configuration file
##

#
# Timeout: The number of seconds before receives and sends time out.
#
Timeout 300

#
# KeepAlive: Whether or not to allow persistent connections (more than
# one request per connection). Set to Off to deactivate.
#
KeepAlive On

#
# MaxKeepAliveRequests: The maximum number of requests to allow
# during a persistent connection. Set to 0 to allow an unlimited amount.
# We recommend you leave this number high, for maximum performance.
#
MaxKeepAliveRequests 100

#
# KeepAliveTimeout: Number of seconds to wait for the next request from the
# same client on the same connection.
#
KeepAliveTimeout 15

#
# Server-pool size regulation.  Rather than making you guess how many
# server processes you need, Apache dynamically adapts to the load it
# sees --- that is, it tries to maintain enough server processes to
# handle the current load, plus a few spare servers to handle transient
# load spikes (e.g., multiple simultaneous requests from a single
# Netscape browser).
#
# It does this by periodically checking how many servers are waiting
# for a request.  If there are fewer than MinSpareServers, it creates
# a new spare.  If there are more than MaxSpareServers, some of the
# spares die off.  The default values are probably OK for most sites.
#
MinSpareServers 5
MaxSpareServers 10

#
# Number of servers to start initially --- should be a reasonable ballpark
# figure.
#
StartServers 8

#
# Limit on total number of servers running, i.e., limit on the number
# of clients who can simultaneously connect --- if this limit is ever
# reached, clients will be LOCKED OUT, so it should NOT BE SET TOO LOW.
# It is intended mainly as a brake to keep a runaway server from taking
# the system with it as it spirals down...
#
MaxClients 150

#
# MaxRequestsPerChild: the number of requests each child process is
# allowed to process before the child dies.  The child will exit so
# as to avoid problems after prolonged use when Apache (and maybe the
# libraries it uses) leak memory or other resources.  On most systems, this
# isn't really needed, but a few (such as Solaris) do have notable leaks
# in the libraries. For these platforms, set to something like 1
# or so; a setting of 0 means unlimited.
#
# NOTE: This value does not include keepalive requests after the initial
#   request per connection. For example, if a child process handles
#   an initial request and 10 subsequent keptalive requests, it
#   would only count as 1 request towards this limit.
#
MaxRequestsPerChild 200

#
# DocumentRoot: The directory out of which you will serve your
# documents. By default, all requests are taken from this directory, but
# symbolic links and aliases may be used to point to other locations.
#
DocumentRoot /usr/local/jakarta-tomcat-3.3.1/webapps/ROOT

# This should be changed to whatever you set DocumentRoot to.
#
Directory /usr/local/jakarta-tomcat-3.3.1/webapps/ROOT

#
# This may also be None, All, or any combination of Indexes,
# Includes, FollowSymLinks, ExecCGI, or MultiViews.
#
# Note that MultiViews must be named *explicitly* --- Options All
# doesn't give it to you.
#
Options  indexes  includes  followSymLinks

#
# This controls which options the .htaccess files in directories can
# override. Can also be All, or any combination of Options, FileInfo,
# AuthConfig, and Limit
#
AllowOverride None

#
# Controls who can get stuff from this server.
#
Order allow,deny
Allow from all
/Directory

# Include TOMCAT
Include /usr/local/jakarta-tomcat-3.3.1/conf/auto/mod_jk.conf-local



-  mod_jk.conf-local -


## Auto generated on Tue Apr 30 11:47:40 WEST 2002##

IfModule !mod_jk.c
  LoadModule jk_module libexec/mod_jk.so
  AddModule mod_jk.c
/IfModule

JkWorkersFile /usr/local/jakarta-tomcat-3.3.1/conf/jk/workers.properties
JkLogFile /usr/local/jakarta-tomcat-3.3.1/logs/mod_jk.log

JkLogLevel error



 /WebApplication 

# Static files
Alias /WebApplication 
/usr/local/jakarta-tomcat-3.3.1/webapps/WebApplication

Directory /usr/local/jakarta-tomcat-3.3.1/webapps/WebApplication
Options Indexes FollowSymLinks
DirectoryIndex index.jsp index.html index.htm