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Posted to users@tomcat.apache.org by Haug Thomas <th...@siemens.com> on 2003/09/01 13:44:00 UTC
Socket Problem with tomcat on Solaris 8
Hi everybody,
I have a problem with tomcat 4.1.24 running on Solaris 8 (with JDK
1.4.1_02).
A client of mine is sending requests to the Tomcat instance in a loop (but
sequentially). After a while the client receives a java.net.ConnectException
with the error message
"Connection timed out: connect". On the server side I do not find any
exception trace in the log files of the Tomcat instance. The only remarkable
thing I detected is that there are thousands of sockets in the TIME WAIT
state: netstat -a | grep "8080" results in
myserver.8080 myclient.1679 7480 0 24820 0 TIME_WAIT
myserver.8080 myclient.1680 7480 0 24820 0 TIME_WAIT
myserver.8080 myclient.1680 7480 0 24820 0 TIME_WAIT
... [many more of these lines]
After a while these sockets get collected by the OS. Then the client runs
again without getting a connection exception (at least for a while then the
'process' repeats).
Has anybody of you experienced a similar behaviour ?
Has anybody of you a solution to this problem: Do I need to configure Tomcat
in a special way or is it a problem of the OS and I have to configure the OS
accordingly. At the moment Tomcat is using the coyote connector in the
following way:
<Connector className="org.apache.coyote.tomcat4.CoyoteConnector"
port="8080"
minProcessors="5" maxProcessors="75" enableLookups="false"
redirectPort="8443" acceptCount="100" debug="0"
connectionTimeout="20000" useURIValidationHack="false"
disableUp
loadTimeout="true"/>
As far as I remember is the 'connectionLinger' time disabled if this
configuration is not set in the connector. Is this correct and does this
configuration affect the problem I am experiencing ?
Thank you very much,
Thomas
Mod jk2 binaries
Posted by Andy Eastham <an...@barllama.demon.co.uk>.
Hi,
Please could anyone tell me why there are no linux binaries for mod jk2
version 2.0.2 under
http://jakarta.apache.org/builds/jakarta-tomcat-connectors/jk2/release/v2.0.
2/
I've got to move something from Solaris to Linux and would be interested to
hear if there's a good reason for this before I embark on a wild goose
chase:-)
Was 2.0.2 a bug fix release that didn't effect linux sop people are using
2.0.1?
Or does 2.0.2 not work on Linux for some reason? If so, does 2.0.1 work OK?
I've got 2.0.2 working fine on Solaris with the binary I downloaded from
under the above URL.
TIA,
Andy
Re: Socket Problem with tomcat on Solaris 8
Posted by "Eric J. Pinnell" <er...@iCky.org>.
Hi,
Other people have had this problem. You might want to try Tomcat 4.1.27
as it has a number of Coyote fixes.
As for Solaris settings here are some that I use: (excuse the cut and
paste)
Install Patch IDs
103582-12 or better -SynFlood & Listen Queue management fix
103597-04 or better -TCP patch
104212-13 or better -HME half/full duplex negotiation patch
103093 Required for Netscape 3.x
In /etc/system
set tcp:tcp_conn_hash_size=8192
set ncsize = 30000
set ufs_inode = 30000
set rlim_fd_max=4096
Changes the maximum allow files open per process
set rlim_fd_cur=1024
Changes the current open files per process
set autoup=240
Number of seconds in age for a memory page to be written to disk
set tune_t_fsflushr=120
Number of seconds between wake up times for the fsflush daemon
NDD Settings
tcp_close_wait_interval to 70000 - miliseconds to wait before reclaiming
the so cket resource
tcp_fin_wait_2_flush_interval to 25000 - miliseconds to wait before
closing soc ket resources that have missed a FIN packet
ip_path_mtu_discovery to 0 - turn off MTU discovery - must retune for IPV6
tcp_conn_req_max_q to 512 - max number of queue size for holding partially
star ted connections
tcp_conn_req_max_q0 to 1024 - number of connections to wait holding before
serv er issues an "unable to connect to server" message
tcp_xmit_hiwat to 65535
tcp_recv_hiwat to 65535 increases the size of the send and receive buffers
tcp_cwnd_max to 65535 - increases the congestion window size used with
congesti on avoidance and slow start - prevents byte overflows in the tcp
stack
tcp_keepalive_interval to 90000 - miliseconds of idle time on keepalive
connect ions
tcp_ip_abort_interval to 90000 - miliseconds of time retransmissions for
connec tions in Established state should be retried. Cleans up hung
connections on web
servers.
tcp_ip_abort_cinterval - 60000 - miliseconds of time retransmissions in
connect ions started but not established will continue. Protects from over
powerful SYN flood attacks as well as dropped proxy connections.
tcp_rexmit_interval_initial to 3000 - miliseconds before a retransmit is
sent -needs to be lowed due to Internet latency
tcp_rexmit_interval_min to 3000 - see above
tcp_rexmit_interval_max to 5000 - see above
tcp_conn_grace_period to 500
ip_ignore_redirect to 1 - ignores IP level redirects
tcp_slow_start_initial to 2 - Microsoft & BSD TCP/IP implementations do
not follow the RFC (2001) for TCP/IP. When communicating with Solaris
this causes a 1- 2 second delay in web page delivery. This fixes.
tcp_deferred_ack_interval to 300 - miliseconds before sending delayed ack
allow s ACK and response to be combined in 1 send for many HTTP requests
-e
On Mon, 1 Sep 2003, Haug Thomas wrote:
> Hi everybody,
>
> I have a problem with tomcat 4.1.24 running on Solaris 8 (with JDK
> 1.4.1_02).
> A client of mine is sending requests to the Tomcat instance in a loop (but
> sequentially). After a while the client receives a java.net.ConnectException
> with the error message
> "Connection timed out: connect". On the server side I do not find any
> exception trace in the log files of the Tomcat instance. The only remarkable
> thing I detected is that there are thousands of sockets in the TIME WAIT
> state: netstat -a | grep "8080" results in
> myserver.8080 myclient.1679 7480 0 24820 0 TIME_WAIT
> myserver.8080 myclient.1680 7480 0 24820 0 TIME_WAIT
> myserver.8080 myclient.1680 7480 0 24820 0 TIME_WAIT
> ... [many more of these lines]
> After a while these sockets get collected by the OS. Then the client runs
> again without getting a connection exception (at least for a while then the
> 'process' repeats).
>
> Has anybody of you experienced a similar behaviour ?
> Has anybody of you a solution to this problem: Do I need to configure Tomcat
> in a special way or is it a problem of the OS and I have to configure the OS
> accordingly. At the moment Tomcat is using the coyote connector in the
> following way:
> <Connector className="org.apache.coyote.tomcat4.CoyoteConnector"
> port="8080"
> minProcessors="5" maxProcessors="75" enableLookups="false"
> redirectPort="8443" acceptCount="100" debug="0"
> connectionTimeout="20000" useURIValidationHack="false"
> disableUp
> loadTimeout="true"/>
> As far as I remember is the 'connectionLinger' time disabled if this
> configuration is not set in the connector. Is this correct and does this
> configuration affect the problem I am experiencing ?
>
> Thank you very much,
> Thomas
>
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