o.apache.coyote.http11.Http11Processor   : 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.Http11InputBuffer.parseRequestLine(Http11InputBuffer.java:
 
422)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:683)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:
 
1455)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:
 
61)
    at java.lang.Thread.run(Thread.java:745)

阿裏雲上弄了一個tomcat，經常半夜發送崩潰，查看日誌發現這個東西，查閱資料發現是Tomcat的header緩沖區大小不夠,只需要在server.xml中增加maxHttpHeaderSize字段即可:

<Connector URIEncoding="UTF-8" port="8080" protocol="org.apache.coyote.http11.Http11NioProtocol"
    useBodyEncodingForURI="false"
    enableLookups="false"
               connectionTimeout="20000"
               redirectPort="8443" maxHttpHeaderSize="你想要的大小"/>

如：

   <Connector port="8080" executor="tomcatThreadPool"
     protocol="HTTP/1.1"
     maxThreads="1000"
     maxHttpHeaderSize="8192"
     minSpareThreads="100"
     maxSpareThreads="200"
     acceptCount="1000"
     maxConnections="1000"
     connectionTimeout="30000"
     keepAliveTimeout="15000"
     maxKeepAliveRequests="1"
      tcpNoDelay="true"
     redirectPort="8443"
     enableLookups="false"
     URIEncoding="UTF-8"/>

http://www.cnblogs.com/yuananyun/p/6501324.html

Invalid character found in method name. HTTP method names must be tokens