André,
> -----Original Message----- > From: André Warnier (tomcat) [mailto:a...@ice-sa.com] > Sent: Tuesday, May 16, 2017 2:00 PM > To: users@tomcat.apache.org > Subject: Re: Can't get over 100 client connections? > > On 16.05.2017 19:57, john.e.gr...@wellsfargo.com.INVALID wrote: > > All, > > > > I'm using Tomcat 7.0.75. > > > > I cannot get my connection or thread count over 100 no matter how much > load I throw at the server. Currently I just have a dummy app deployed that > doesn't do much except sleep for about 500ms and return a canned > response. Initially I had maxThreads=20 with no explicit maxConnections. I > could get the "current threads busy" metric to 20 easily. Then I raised it to > 100 and was able to reach that number easily. Additionally, netstat told me I > had 100 incoming connections to port 5114. However raising the maxThreads > higher doesn't make any difference, nor does explicitly specifying > maxConnections=200. In either case, I can only get 100 busy threads and 100 > active connections. Once I reach that limit, the response times on the client > start going up. The Tomcat server itself isn't stressed at all. CPU and GC > are > low. The client is on a different server in the same data center. > > > > I'm not going through a load balancer. I'm going directly to the connector > below: > > > > > > <Connector port="5114" > > protocol="HTTP/1.1" > > SSLEnabled="true" > > maxConnections="200" > > maxThreads="200" > > maxKeepAliveRequests="100" > > keepAliveTimeout="10000" > > scheme="https" > > secure="true" > > clientAuth="true" > > sslProtocol="TLS" > > keystoreFile="/app/comp/myapp/certs/appcerttestkeystore" > > keystorePass="${keystore.password}" > > keyAlias="test" > > truststoreFile="/app/comp/myapp/certs/cacerts" > > truststorePass="${truststore.password}" > > allowUnsafeLegacyRenegotiation="false" > > ciphers="blah blah blah" > > /> > > > > Hi. > I do not know with what you are testing (as a client). > But be aware of the following : > > 1) > keepAliveTimeout="10000" > means 10 seconds. > It means that, after the last request which one particular client sends on its > connection to Tomcat, and Tomcat has responded to it, Tomcat will keep that > connection open for an additional 10 s., just waiting to see if that same > client > has anything more to request. > Since you are not using an Executor, keeping the connection open will also > mean keeping the corresponding Tomcat thread alive, also waiting. > Only once this time is over, will Tomcat close this connection, and "recycle" > the thread to serve another client connection. > 2) there may be a limit in the server OS, as to how many connections a > process can have open at the same time. If that limit is reached at some > point, that may either crash the process that wants an additional one, or put > it in some wait queue until one is available again. > 3) when a client opens a connection to a server (or tries to), and the server > process does not immediately respond to the "open connection" request, > the TCP/IP stack on the server will place the connection-open request in a > wait queue. The size of that queue is an adjustable TCP/IP parameter. > From the client side, if its connection is not accepted immediately (but not > rejected right away), the client will just wait, until it is accepted. There > is > usually a timeout for this also, on the client side. > > Some combination of the above may explain what you see. > Thanks for the suggestions. I don't know 100% the cause yet but it appears to be an issue on the client side. When running multiple clients I can get the concurrent requests over 100 with no trouble. Thanks --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
