Hello, Last November, my tomcat webapps was suddenly not working. I restarted tomcat service and it's come back to normal state.
Access log returned 400 for request at the time Time Taken: 0.000 0 10.176.94.121 - - [20/Nov/2019:17:54:32 +0800] "-" 400 - Time Taken: 0.000 0 10.176.94.121 - - [20/Nov/2019:17:54:32 +0800] "-" 400 - Time Taken: 0.000 0 10.176.94.121 - - [20/Nov/2019:18:01:45 +0800] "-" 400 - Time Taken: 0.000 0 10.176.94.121 - - [20/Nov/2019:18:01:45 +0800] "-" 400 - >From Catalina log, before the time that I cannot access webapp, there is some >log as below: Nov 20, 2019 5:54:32 PM org.apache.coyote.http11.AbstractHttp11Processor process INFO: Error parsing HTTP request header Note: further occurrences of HTTP header parsing errors will be logged at DEBUG level. java.lang.IllegalArgumentException: Invalid character found in method name. HTTP method names must be tokens at org.apache.coyote.http11.InternalInputBuffer.parseRequestLine(InternalInputBuffer.java:135) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:996) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:623) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745) Nov 20, 2019 6:01:45 PM org.apache.coyote.http11.AbstractHttp11Processor process INFO: Error parsing HTTP request header Note: further occurrences of HTTP header parsing errors will be logged at DEBUG level. java.lang.IllegalArgumentException: Invalid character found in method name. HTTP method names must be tokens at org.apache.coyote.http11.InternalInputBuffer.parseRequestLine(InternalInputBuffer.java:135) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:996) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:623) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745) As there is no others error, I can't know why it was not working. Could you please help check if those error can made the tomcat to hang and webapps cannot access? Thank you very much.