RE: please help me how i can test that whether tomcat is up and running on
And the key to the proper answer is this bit from the OP: please help me how i can test that whether tomcat is up and running on a remote machine from a client machine. The proper answer is he can't, as the server is only listening to the port via the localhost IP (aka loopback). There is no way he will ever be able to check status this way from a client (remote) system. -Original Message- From: André Warnier [mailto:a...@ice-sa.com] Sent: Thursday, September 22, 2011 3:21 PM To: Tomcat Users List Subject: Re: please help me how i can test that whether tomcat is up and running on Hi. This is all very nicely explained, but maybe irrelevant. As far as I understand, the OP is trying to connect to the shutdown port mentioned in the Server tag, not to a Connector. On that shutdown port, there should not be so many connection requests that they outrun the ability of Tomcat to accept a connection on it. I have a suspicion that the client does not connect to Tomcat though, maybe not even to the Tomcat host. But the OP did not really provide enough information to validate or invalidate that suspicion. Daniel Baktiar wrote: Hi Vishveswara, If you look at the behavior of ServerSocket, or any BSD-like listening server socket in general, there is something called 'backlog'. http://download.oracle.com/javase/1.4.2/docs/api/java/net/ServerSocket. html In short, backlog is something like a queue, if all your worker thread occupied, the listening server socket is allowed to hold and queue n number of connecting socket. Only when the all threads occupied and backlog full then you will get connection refused. The connection socket in the backlog is silently accepted but not served yet. If the connection socket was held in the backlog for quite some time (e.g. due to existing worker threads still busy), until it is time out for the connection client socket, then that what you have said may occur: the Tomcat is up and running, yet the connection client socket java.net.ConnectException: Connection timeout: connect. So, what you can detect by a connection client socket is not whether Tomcat is up and running, instead whether Tomcat is up and running and able to accept and process one more client socket within the client time out interval. There are cases where Tomcat is up and running but is not able to accept and process one more client socket within the client time out interval (which is the case when java.net.ConnectException: Connection timeout: connect happens). There is an acceptCount attribute in server.xml Connector / which specifies the backlog. If you set this to 0, it may behave the way you want, but you have to test yourself whether that will be good for the system behaviour and performance from the user point of view. --- daniel baktiar On Thu, Sep 22, 2011 at 18:30, vishveswara chary varanasi vvchary.varan...@gmail.com wrote: Tomcat community has a wiki which providded the http://wiki.apache.org/tomcat/HowTo#How_do_I_check_whether_Tomcat_is_UP _or_DOWN.3F_There_is_no_status_command i have tried to connect to tomcat using sockect connection on the port where the tomcat running Socket socket = new Socket(hostname, port); this works some time and some time even if the tomcat is up and runnning this is throwing the java.net.ConnectException: Connection timed out: connect. please help me how i can test that whether tomcat is up and running on a remote machine from a client machine. Thanks - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org __ Confidentiality Notice: This Transmission (including any attachments) may contain information that is privileged, confidential, and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient you are hereby notified that any dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this transmission in error, please immediately reply to the sender or telephone (512) 343-9100 and delete this transmission from your system.
Re: please help me how i can test that whether tomcat is up and running on
Coming late to the party, hm ? Jeffrey Janner wrote: And the key to the proper answer is this bit from the OP: please help me how i can test that whether tomcat is up and running on a remote machine from a client machine. The proper answer is he can't, as the server is only listening to the port via the localhost IP (aka loopback). There is no way he will ever be able to check status this way from a client (remote) system. As was mentioned in the first answer to the OP's post, on 22/9. But the OP himself seems to have lost interest a long time ago, and never even posted a message indicating whether he had solved his problem. Ungrateful, they are. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: please help me how i can test that whether tomcat is up and running on a remote machine from a client machine.
vishveswara chary varanasi wrote: Tomcat community has a wiki which providded the http://wiki.apache.org/tomcat/HowTo#How_do_I_check_whether_Tomcat_is_UP_or_DOWN.3F_There_is_no_status_command i have tried to connect to tomcat using sockect connection on the port where the tomcat running which is ? Socket socket = new Socket(hostname, port); What is hostname in your case ? can the client resolve this name to an IP address corresponding to the Tomcat host ? this works some time and some time even if the tomcat is up and runnning this is throwing the java.net.ConnectException: Connection timed out: connect. When does it work and when not ? please help me how i can test that whether tomcat is up and running on a remote machine from a client machine. Read this carefully : http://tomcat.apache.org/tomcat-7.0-doc/config/server.html (all of it, but particularly the address attribute). Unless I am mistaken, it means that by default Tomcat only listens, on that port, on the address localhost, which usually is the IP address 127.0.0.1. In other words, by default this will only work from a client running on the same host. By using e.g. : address=0.0.0.0 you could tell Tomcat to bind this listening socket to all the IP addresses of the Tomcat host. But then, you have to be extra careful not to allow just any client to stop Tomcat, just by connecting to that IP/port and sending SHUTDOWN. - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: please help me how i can test that whether tomcat is up and running on
Hi Vishveswara, If you look at the behavior of ServerSocket, or any BSD-like listening server socket in general, there is something called 'backlog'. http://download.oracle.com/javase/1.4.2/docs/api/java/net/ServerSocket.html In short, backlog is something like a queue, if all your worker thread occupied, the listening server socket is allowed to hold and queue n number of connecting socket. Only when the all threads occupied and backlog full then you will get connection refused. The connection socket in the backlog is silently accepted but not served yet. If the connection socket was held in the backlog for quite some time (e.g. due to existing worker threads still busy), until it is time out for the connection client socket, then that what you have said may occur: the Tomcat is up and running, yet the connection client socket java.net.ConnectException: Connection timeout: connect. So, what you can detect by a connection client socket is not whether Tomcat is up and running, instead whether Tomcat is up and running and able to accept and process one more client socket within the client time out interval. There are cases where Tomcat is up and running but is not able to accept and process one more client socket within the client time out interval (which is the case when java.net.ConnectException: Connection timeout: connect happens). There is an acceptCount attribute in server.xml Connector / which specifies the backlog. If you set this to 0, it may behave the way you want, but you have to test yourself whether that will be good for the system behaviour and performance from the user point of view. --- daniel baktiar On Thu, Sep 22, 2011 at 18:30, vishveswara chary varanasi vvchary.varan...@gmail.com wrote: Tomcat community has a wiki which providded the http://wiki.apache.org/tomcat/HowTo#How_do_I_check_whether_Tomcat_is_UP_or_DOWN.3F_There_is_no_status_command i have tried to connect to tomcat using sockect connection on the port where the tomcat running Socket socket = new Socket(hostname, port); this works some time and some time even if the tomcat is up and runnning this is throwing the java.net.ConnectException: Connection timed out: connect. please help me how i can test that whether tomcat is up and running on a remote machine from a client machine. Thanks - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: please help me how i can test that whether tomcat is up and running on
Hi. This is all very nicely explained, but maybe irrelevant. As far as I understand, the OP is trying to connect to the shutdown port mentioned in the Server tag, not to a Connector. On that shutdown port, there should not be so many connection requests that they outrun the ability of Tomcat to accept a connection on it. I have a suspicion that the client does not connect to Tomcat though, maybe not even to the Tomcat host. But the OP did not really provide enough information to validate or invalidate that suspicion. Daniel Baktiar wrote: Hi Vishveswara, If you look at the behavior of ServerSocket, or any BSD-like listening server socket in general, there is something called 'backlog'. http://download.oracle.com/javase/1.4.2/docs/api/java/net/ServerSocket.html In short, backlog is something like a queue, if all your worker thread occupied, the listening server socket is allowed to hold and queue n number of connecting socket. Only when the all threads occupied and backlog full then you will get connection refused. The connection socket in the backlog is silently accepted but not served yet. If the connection socket was held in the backlog for quite some time (e.g. due to existing worker threads still busy), until it is time out for the connection client socket, then that what you have said may occur: the Tomcat is up and running, yet the connection client socket java.net.ConnectException: Connection timeout: connect. So, what you can detect by a connection client socket is not whether Tomcat is up and running, instead whether Tomcat is up and running and able to accept and process one more client socket within the client time out interval. There are cases where Tomcat is up and running but is not able to accept and process one more client socket within the client time out interval (which is the case when java.net.ConnectException: Connection timeout: connect happens). There is an acceptCount attribute in server.xml Connector / which specifies the backlog. If you set this to 0, it may behave the way you want, but you have to test yourself whether that will be good for the system behaviour and performance from the user point of view. --- daniel baktiar On Thu, Sep 22, 2011 at 18:30, vishveswara chary varanasi vvchary.varan...@gmail.com wrote: Tomcat community has a wiki which providded the http://wiki.apache.org/tomcat/HowTo#How_do_I_check_whether_Tomcat_is_UP_or_DOWN.3F_There_is_no_status_command i have tried to connect to tomcat using sockect connection on the port where the tomcat running Socket socket = new Socket(hostname, port); this works some time and some time even if the tomcat is up and runnning this is throwing the java.net.ConnectException: Connection timed out: connect. please help me how i can test that whether tomcat is up and running on a remote machine from a client machine. Thanks - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: please help me how i can test that whether tomcat is up and running on
Oops. I missed that. You've pointed it straight! --- daniel baktiar On Fri, Sep 23, 2011 at 04:20, André Warnier a...@ice-sa.com wrote: Hi. This is all very nicely explained, but maybe irrelevant. As far as I understand, the OP is trying to connect to the shutdown port mentioned in the Server tag, not to a Connector. On that shutdown port, there should not be so many connection requests that they outrun the ability of Tomcat to accept a connection on it. I have a suspicion that the client does not connect to Tomcat though, maybe not even to the Tomcat host. But the OP did not really provide enough information to validate or invalidate that suspicion. Daniel Baktiar wrote: Hi Vishveswara, If you look at the behavior of ServerSocket, or any BSD-like listening server socket in general, there is something called 'backlog'. http://download.oracle.com/**javase/1.4.2/docs/api/java/** net/ServerSocket.htmlhttp://download.oracle.com/javase/1.4.2/docs/api/java/net/ServerSocket.html In short, backlog is something like a queue, if all your worker thread occupied, the listening server socket is allowed to hold and queue n number of connecting socket. Only when the all threads occupied and backlog full then you will get connection refused. The connection socket in the backlog is silently accepted but not served yet. If the connection socket was held in the backlog for quite some time (e.g. due to existing worker threads still busy), until it is time out for the connection client socket, then that what you have said may occur: the Tomcat is up and running, yet the connection client socket java.net.ConnectException: Connection timeout: connect. So, what you can detect by a connection client socket is not whether Tomcat is up and running, instead whether Tomcat is up and running and able to accept and process one more client socket within the client time out interval. There are cases where Tomcat is up and running but is not able to accept and process one more client socket within the client time out interval (which is the case when java.net.ConnectException: Connection timeout: connect happens). There is an acceptCount attribute in server.xml Connector / which specifies the backlog. If you set this to 0, it may behave the way you want, but you have to test yourself whether that will be good for the system behaviour and performance from the user point of view. --- daniel baktiar On Thu, Sep 22, 2011 at 18:30, vishveswara chary varanasi vvchary.varan...@gmail.com wrote: Tomcat community has a wiki which providded the http://wiki.apache.org/tomcat/**HowTo#How_do_I_check_whether_** Tomcat_is_UP_or_DOWN.3F_There_**is_no_status_commandhttp://wiki.apache.org/tomcat/HowTo#How_do_I_check_whether_Tomcat_is_UP_or_DOWN.3F_There_is_no_status_command i have tried to connect to tomcat using sockect connection on the port where the tomcat running Socket socket = new Socket(hostname, port); this works some time and some time even if the tomcat is up and runnning this is throwing the java.net.ConnectException: Connection timed out: connect. please help me how i can test that whether tomcat is up and running on a remote machine from a client machine. Thanks --**--** - To unsubscribe, e-mail: users-unsubscribe@tomcat.**apache.orgusers-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org --**--**- To unsubscribe, e-mail: users-unsubscribe@tomcat.**apache.orgusers-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
