Re: how http connector backlog attribute works?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA256 侯树成, On 12/27/13, 4:24 AM, 侯树成 wrote: Yes, this must use BIO mode, because the NIO maxConnections=1 in default, it won't block the LimitLatch. In my test case,(use JMeter, thread number is 5), 2 requests will refused soon(just 1s-2s later), then another 3 requests will served correctly.In source code, I find the backlog attribute will send to ServerSocket constructor, So, the backlog attribute is worked inside of JDK, not in Tomcat? The backlog is technically handled in the OS kernel/TCP stack. This page is Linux-specific, but implements a BSD standard. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1 Comment: GPGTools - http://gpgtools.org Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBCAAGBQJSwaKaAAoJEBzwKT+lPKRYuwQP/2loOTXAeSXg15ptpUPOcRH6 8bKk/zf5bxuUCClrYSEaxiDT+RpD8yINynGZRrR+c+wVYuOBoKSSoFwpoFFgovrk 8KvNZHC6GC3/qDwDGs4t69cuiN/KBjLiSygJI/arxIoxDVbc1jKUzUsvGpBYC4Hm FdiTddvyslQy+xR8Klw1Ak4ccTYKcZSPXDXZ/s9z8ELYlswAWq7LGRSJqdJI2BNG Ja92dLSEQ4NTHSxfEXeWusrf51tJFqXLq1kjfALGlXdL9FC05Phc+PCXPBAbcQsW acaUMy6ry8aqtZ3rdAdIHFSjxqHtxr5Ffehe8VmjcGXYqWBa7ez6q8zd+Ku9BDBB NCna9X8NFRZT4J8/uJxaXiAiUvxUVEBG4uwRTMx8UebKWQNm8v25tKMHl0z0T/Jt /YsqoTFjQ8/KniDrKaqTcn9BrQLiiTFUTI26t9e7S0V5xF2r8Pk98mkf0mCDl2+7 D7GCGAOwkOhyMFc9fQ2PGKzlKb3EjCas5+7ICRp6qFoa2NLvRls64E6iLlcAEcf1 lC86qqJbHVhE1KNAmSS0pGo/b7zTi54LkssmPzg7Z/3iJ0ugL0KbamPMfetr1HYP 9yINYpVlJK55zKgsvOz63UnUnciDJGxf9IRrgcGNZSaupPKbtj15ewqNLBr30X4F sRcDOHUX8RdojgBljhAX =ZYMg -END PGP SIGNATURE- - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: how http connector backlog attribute works?
Hi, Today, I find the acceptCount of connector is not work like it's config. You can try it like this: Connector port=8080 protocol=HTTP/1.1 connectionTimeout=2 redirectPort=8443 acceptCount=2 maxThreads=1 minSpareThreads=1/ Also use LR/JMeter make more requests( 10) . You will find that 5 requests will served correctly, others will be refused. When the acceptCount=3 Connector port=8080 protocol=HTTP/1.1 connectionTimeout=2 redirectPort=8443 acceptCount=3 maxThreads=1 minSpareThreads=1/ You will find that 7 requests will served correctly, others will be refused. When the acceptCount=4 Connector port=8080 protocol=HTTP/1.1 connectionTimeout=2 redirectPort=8443 acceptCount=4 maxThreads=1 minSpareThreads=1/ Also use LR/JMeter make more requests( 10) . You will find that 9 requests will served correctly, others will be refused. Yes, the SUCCESS requests = 2 * acceptCount + maxthead , is it right? why the acceptCount is not work like it's configuration? Could you help me? 2013/12/27 侯树成 chain...@gmail.com Yes, this must use BIO mode, because the NIO maxConnections=1 in default, it won't block the LimitLatch. In my test case,(use JMeter, thread number is 5), 2 requests will refused soon(just 1s-2s later), then another 3 requests will served correctly.In source code, I find the backlog attribute will send to ServerSocket constructor, So, the backlog attribute is worked inside of JDK, not in Tomcat? Thank you all for reply. 2013/12/27 Mark Thomas ma...@apache.org On 27/12/2013 08:53, Mark Eggers wrote: On 12/27/2013 12:37 AM, Mark Thomas wrote: On 27/12/2013 07:27, Mark Eggers wrote: On 12/26/2013 11:09 PM, 侯树成 wrote: 1.set tomcat connector like this: Connector port=8080 protocol=HTTP/1.1 connectionTimeout=2 redirectPort=8443 acceptCount=1 maxThreads=1 minSpareThreads=1/ 2. deploy a war file, which contains a servlet that will sleep 60s in it's doPost method 3. use LR or JMeter send 5 requests to the serlvet above I'm going to guess based on the Tomcat 7 documentation: request 1 gets executed and sits in your doPost for 60 seconds request 2 consumes the minSpareThread request 3 consumes the acceptCount Per documentation, connections 4 and 5 are dropped immediately. That is almost right except that there should not be a spare thread at step 2 since maxThreads includes any spare threads. Yep, that's what I would expect as well. I was just trying to rationalize the third accept. I agree, I would think that 1 would be served, 2 would wait, and 3-5 would be dropped. Figured it out. The OP is using BIO where maxConnections == maxThreads by default. Request 1 uses the one available request processing thread. Request 2 is accepted but is blocked since the maximum number of connections has been reached. Request 3 uses the accept count. Requests 4 5 are blocked. It might be worth a note in the docs that the number of connections accepted will always be maxConnections + 1 with the + 1 being blocked in the acceptor thread until the number of connections drops below maxConnections again. I'll try and add something later today. Mark - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: how http connector backlog attribute works?
On 27/12/2013 07:27, Mark Eggers wrote: On 12/26/2013 11:09 PM, 侯树成 wrote: 1.set tomcat connector like this: Connector port=8080 protocol=HTTP/1.1 connectionTimeout=2 redirectPort=8443 acceptCount=1 maxThreads=1 minSpareThreads=1/ 2. deploy a war file, which contains a servlet that will sleep 60s in it's doPost method 3. use LR or JMeter send 5 requests to the serlvet above I'm going to guess based on the Tomcat 7 documentation: request 1 gets executed and sits in your doPost for 60 seconds request 2 consumes the minSpareThread request 3 consumes the acceptCount Per documentation, connections 4 and 5 are dropped immediately. That is almost right except that there should not be a spare thread at step 2 since maxThreads includes any spare threads. I'd expect request 2 to use the accept count and 3, 4 5 to be dropped. There may be an off-by-one error somewhere or it could just be an artefact of how the limit is enforced. Please read the following and see if my interpretation is reasonable: http://tomcat.apache.org/tomcat-7.0-doc/config/http.html Pay particular attention to the Introduction section. If I have the particulars wrong, hopefully someone will come along and correct me. Mark - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: how http connector backlog attribute works?
On 12/27/2013 12:37 AM, Mark Thomas wrote: On 27/12/2013 07:27, Mark Eggers wrote: On 12/26/2013 11:09 PM, 侯树成 wrote: 1.set tomcat connector like this: Connector port=8080 protocol=HTTP/1.1 connectionTimeout=2 redirectPort=8443 acceptCount=1 maxThreads=1 minSpareThreads=1/ 2. deploy a war file, which contains a servlet that will sleep 60s in it's doPost method 3. use LR or JMeter send 5 requests to the serlvet above I'm going to guess based on the Tomcat 7 documentation: request 1 gets executed and sits in your doPost for 60 seconds request 2 consumes the minSpareThread request 3 consumes the acceptCount Per documentation, connections 4 and 5 are dropped immediately. That is almost right except that there should not be a spare thread at step 2 since maxThreads includes any spare threads. Yep, that's what I would expect as well. I was just trying to rationalize the third accept. I agree, I would think that 1 would be served, 2 would wait, and 3-5 would be dropped. I'd expect request 2 to use the accept count and 3, 4 5 to be dropped. There may be an off-by-one error somewhere or it could just be an artefact of how the limit is enforced. Please read the following and see if my interpretation is reasonable: http://tomcat.apache.org/tomcat-7.0-doc/config/http.html Pay particular attention to the Introduction section. If I have the particulars wrong, hopefully someone will come along and correct me. Mark I guess some tests are in order? /mde/ - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: how http connector backlog attribute works?
On 27/12/2013 08:53, Mark Eggers wrote: On 12/27/2013 12:37 AM, Mark Thomas wrote: On 27/12/2013 07:27, Mark Eggers wrote: On 12/26/2013 11:09 PM, 侯树成 wrote: 1.set tomcat connector like this: Connector port=8080 protocol=HTTP/1.1 connectionTimeout=2 redirectPort=8443 acceptCount=1 maxThreads=1 minSpareThreads=1/ 2. deploy a war file, which contains a servlet that will sleep 60s in it's doPost method 3. use LR or JMeter send 5 requests to the serlvet above I'm going to guess based on the Tomcat 7 documentation: request 1 gets executed and sits in your doPost for 60 seconds request 2 consumes the minSpareThread request 3 consumes the acceptCount Per documentation, connections 4 and 5 are dropped immediately. That is almost right except that there should not be a spare thread at step 2 since maxThreads includes any spare threads. Yep, that's what I would expect as well. I was just trying to rationalize the third accept. I agree, I would think that 1 would be served, 2 would wait, and 3-5 would be dropped. Figured it out. The OP is using BIO where maxConnections == maxThreads by default. Request 1 uses the one available request processing thread. Request 2 is accepted but is blocked since the maximum number of connections has been reached. Request 3 uses the accept count. Requests 4 5 are blocked. It might be worth a note in the docs that the number of connections accepted will always be maxConnections + 1 with the + 1 being blocked in the acceptor thread until the number of connections drops below maxConnections again. I'll try and add something later today. Mark - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: how http connector backlog attribute works?
Yes, this must use BIO mode, because the NIO maxConnections=1 in default, it won't block the LimitLatch. In my test case,(use JMeter, thread number is 5), 2 requests will refused soon(just 1s-2s later), then another 3 requests will served correctly.In source code, I find the backlog attribute will send to ServerSocket constructor, So, the backlog attribute is worked inside of JDK, not in Tomcat? Thank you all for reply. 2013/12/27 Mark Thomas ma...@apache.org On 27/12/2013 08:53, Mark Eggers wrote: On 12/27/2013 12:37 AM, Mark Thomas wrote: On 27/12/2013 07:27, Mark Eggers wrote: On 12/26/2013 11:09 PM, 侯树成 wrote: 1.set tomcat connector like this: Connector port=8080 protocol=HTTP/1.1 connectionTimeout=2 redirectPort=8443 acceptCount=1 maxThreads=1 minSpareThreads=1/ 2. deploy a war file, which contains a servlet that will sleep 60s in it's doPost method 3. use LR or JMeter send 5 requests to the serlvet above I'm going to guess based on the Tomcat 7 documentation: request 1 gets executed and sits in your doPost for 60 seconds request 2 consumes the minSpareThread request 3 consumes the acceptCount Per documentation, connections 4 and 5 are dropped immediately. That is almost right except that there should not be a spare thread at step 2 since maxThreads includes any spare threads. Yep, that's what I would expect as well. I was just trying to rationalize the third accept. I agree, I would think that 1 would be served, 2 would wait, and 3-5 would be dropped. Figured it out. The OP is using BIO where maxConnections == maxThreads by default. Request 1 uses the one available request processing thread. Request 2 is accepted but is blocked since the maximum number of connections has been reached. Request 3 uses the accept count. Requests 4 5 are blocked. It might be worth a note in the docs that the number of connections accepted will always be maxConnections + 1 with the + 1 being blocked in the acceptor thread until the number of connections drops below maxConnections again. I'll try and add something later today. Mark - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
how http connector backlog attribute works?
Hi, I find a problem of http bio connector,I need help. You can find it in flowing steps: 1.set tomcat connector like this: Connector port=8080 protocol=HTTP/1.1 connectionTimeout=2 redirectPort=8443 acceptCount=1 maxThreads=1 minSpareThreads=1/ 2. deploy a war file, which contains a servlet that will sleep 60s in it's doPost method 3. use LR or JMeter send 5 requests to the serlvet above 4. use command jstack print current thread stack NOTE: now the main acceptor thread stack like this: http-bio-8080-Acceptor-0 daemon prio=6 tid=0x04b49800 nid=0x1a88 waiting on condition [0x0536f000] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for 0x29a06cd0 (a org.apache.tomcat.util.threads.LimitLatch$Sync) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:156) at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:811) at java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:969) at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1281) at org.apache.tomcat.util.threads.LimitLatch.countUpOrAwait(LimitLatch.java:115) at org.apache.tomcat.util.net.AbstractEndpoint.countUpOrAwaitConnection(AbstractEndpoint.java:733) at org.apache.tomcat.util.net.JIoEndpoint$Acceptor.run(JIoEndpoint.java:210) at java.lang.Thread.run(Thread.java:662) Now, In the 5 requests, 3 request will served correctly, but another 2 requests will received Connection refused error like this Caused by: java.net.ConnectException: Connection refused: connect at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351) at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:213) at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:200) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366) at java.net.Socket.connect(Socket.java:529) Why the 2 requests not entering the thread pool executor or taskQueue, but get refused quickly? Thanks in advance.
Re: how http connector backlog attribute works?
侯树成 wrote: Hi, I find a problem of http bio connector,I need help. You can find it in flowing steps: 1.set tomcat connector like this: Connector port=8080 protocol=HTTP/1.1 connectionTimeout=2 redirectPort=8443 acceptCount=1 maxThreads=1 minSpareThreads=1/ 2. deploy a war file, which contains a servlet that will sleep 60s in it's doPost method 3. use LR or JMeter send 5 requests to the serlvet above 4. use command jstack print current thread stack NOTE: now the main acceptor thread stack like this: http-bio-8080-Acceptor-0 daemon prio=6 tid=0x04b49800 nid=0x1a88 waiting on condition [0x0536f000] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for 0x29a06cd0 (a org.apache.tomcat.util.threads.LimitLatch$Sync) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:156) at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:811) at java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:969) at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1281) at org.apache.tomcat.util.threads.LimitLatch.countUpOrAwait(LimitLatch.java:115) at org.apache.tomcat.util.net.AbstractEndpoint.countUpOrAwaitConnection(AbstractEndpoint.java:733) at org.apache.tomcat.util.net.JIoEndpoint$Acceptor.run(JIoEndpoint.java:210) at java.lang.Thread.run(Thread.java:662) Now, In the 5 requests, 3 request will served correctly, but another 2 requests will received Connection refused error like this Caused by: java.net.ConnectException: Connection refused: connect at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351) at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:213) at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:200) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366) at java.net.Socket.connect(Socket.java:529) Why the 2 requests not entering the thread pool executor or taskQueue, but get refused quickly? Thanks in advance. Which java and Tomcat versions ? - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: how http connector backlog attribute works?
On 12/26/2013 11:09 PM, 侯树成 wrote: Hi, I find a problem of http bio connector,I need help. You can find it in flowing steps: 1.set tomcat connector like this: Connector port=8080 protocol=HTTP/1.1 connectionTimeout=2 redirectPort=8443 acceptCount=1 maxThreads=1 minSpareThreads=1/ 2. deploy a war file, which contains a servlet that will sleep 60s in it's doPost method 3. use LR or JMeter send 5 requests to the serlvet above 4. use command jstack print current thread stack NOTE: now the main acceptor thread stack like this: http-bio-8080-Acceptor-0 daemon prio=6 tid=0x04b49800 nid=0x1a88 waiting on condition [0x0536f000] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for 0x29a06cd0 (a org.apache.tomcat.util.threads.LimitLatch$Sync) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:156) at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:811) at java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:969) at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1281) at org.apache.tomcat.util.threads.LimitLatch.countUpOrAwait(LimitLatch.java:115) at org.apache.tomcat.util.net.AbstractEndpoint.countUpOrAwaitConnection(AbstractEndpoint.java:733) at org.apache.tomcat.util.net.JIoEndpoint$Acceptor.run(JIoEndpoint.java:210) at java.lang.Thread.run(Thread.java:662) Now, In the 5 requests, 3 request will served correctly, but another 2 requests will received Connection refused error like this Caused by: java.net.ConnectException: Connection refused: connect at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351) at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:213) at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:200) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366) at java.net.Socket.connect(Socket.java:529) Why the 2 requests not entering the thread pool executor or taskQueue, but get refused quickly? Thanks in advance. I'm going to guess based on the Tomcat 7 documentation: request 1 gets executed and sits in your doPost for 60 seconds request 2 consumes the minSpareThread request 3 consumes the acceptCount Per documentation, connections 4 and 5 are dropped immediately. Please read the following and see if my interpretation is reasonable: http://tomcat.apache.org/tomcat-7.0-doc/config/http.html Pay particular attention to the Introduction section. If I have the particulars wrong, hopefully someone will come along and correct me. . . . just my two cents /mde/ - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
