Hi.
There are a number of problems with your post, which make it difficult to understand
exactly what you want to know.
Dhaval Jaiswal wrote:
acceptCount variable:
Following is the current configuration in server.xml I am using version. 6.
Connector port=8080 protocol=HTTP/1.1
connectionTimeout=2
redirectPort=8443
That tag is incomplete.
Resource name=jdbc/DB_NAME auth=Container type=javax.sql.DataSource
driverClassName=org.
postgresql.Driver url=jdbc:postgresql://IP:PORT/DB_NAME
username= password=
maxActive=100 maxIdle=20 maxWait=3
validationQuery=select 1 testOnBorrow=true
removeAbandoned=true removeAbandonedTimeout=120
logAbandoned=true /
That tag is also incomplete, and it has basically nothing to do with the Connector tag
above (nor with acceptCount or maxThreads).
Planning to add below parameters.
maxThreads=2
acceptCount=500
Where ?
The situation I got is some times i am not getting timely response from the
outsiders.
What is the outsiders ? The browser clients trying to get a connection to Tomcat, or
the postgres database which you seem to be using for authentication ?
In this case i need to make the bigger queue in connection pool.
What connection pool ?
As per document and forums says default queue size of acceptCount is 100.
During the time if new connection request comes in it simply refuse it.
That has nothing to do with any connection pool.
A new connection (from a client) will be refused if :
- all Tomcat threads of the Connector are already busy handling other requests
AND
- there are already acceptCount previous connection requests waiting for an accept in
the accept queue of the Connector
1)
I just do not want to refuse the new connection, but want to keep that
connection in a pool.
That does not really make sense, as a phrase.
I want to make the queue size of 500 and if possible
more than that.
Why ?
What is your opinion on below configuration. Will it help me. Is it going
to degrade the performance if i will increase the value of acceptCount
variable along with maxThreads.
maxThreads=2
acceptCount=500
These two parameters are not directly related, and each of those parameters should only be
modified (compared to the default) in very specific circumstances.
We cannot have an opinion on whether changing one or the other will help or not, before we
know
1) if you really have a problem now, or if you are just speculating without real facts. If
you have a real problem, what is it ? is your Tomcat really refusing browser connections ?
if yes, does this happen all the time, or only at specific times ?
2) what is the expected load of your server ? how many clients are expected to connect to
your server at the same time ? how many HTTP requests are you expecting to have to process
at the same time ? how long does it take, on average, to process one request ?
3) what are the characteristics of your server ? (how fast is the CPU, how much memory
does it have, how much of that is available to Tomcat)
etc..
Here are some general tips :
1) the default parameters of Tomcat are set by people who know what they are doing, in a
way that they determine is appropriate for the large majority of practical cases.
There are thousands of Tomcats which are running fine on the WWW, using these default
parameters. Changing them without knowing why, and without konwing exactly what effect
they have, is more likely to make the situation worse, than improving it.
2) to determine if you need to change a parameter, and which parameter to change and how
to change it, you need first to *measure* what is happening.
2) the acceptCount of the Connector is a parameter which relates to the TCP/IP stack of
your machine. Tomcat just passes this parameter to the underlying OS, when it opens the
TCP socket which is used by this Connector. It is the TCP/IP stack of the OS which is
going to refuse new client connections, if the accept queue fills up.
The accept queue fills up, when Tomcat (for any of many possible reasons) cannot handle
anymore the number of client requests which arrive over a period of time.
3) the maxThreads parameter of a Connector, represents how many threads maximum, this
Connector can start at the same time. Each of those threads handles one request of one
client. So, *if you know* :
a) that it takes on average 1 second for your Tomcat (and your webapp) to
process one request
b) that, sometimes, there can be 300 clients sending one request each to your Tomcat over
1 second (for a total of 300 requests over the same second)
then, you would know that you need to set the maxThreads parameter to (at
least) 300.
If processing one request takes on average 2 seconds, then if during 1 second Tomcat can
receive 300 requests, you will need to set maxThreads higher (because at the end of this
first second, the first 300 threads
