Tomcat 7.0.43 "Info: Error Parsing Http Request Header"

For me, the problem was passing in a larger than normally expected HTTP header. I resolved it by setting maxHttpHeaderSize="1048576" attribute on the Connector node in server.xml.

If there are too many cookies cached, it breaks the server (the size of a request header is too big!). Clearing the cookies can fix this issue as well.

I had a similar issue, I was sending a POST request (using RESTClient plugin for Firefox) with data in the request body and was receiving the same message.

In my case this happened because I was trying to use HTTPS protocol in a local tomcat instance where HTTPS was not configured.

Check, if you are not accidentally requesting HTTPS protocol instead of HTTP.

I have overlooked that I was requesting instead of and it resulted to this weird message..

My problem occurs when I try to open https. I don't use SSL.

It's Tomcat bug.

Today 12/02/2017 newest official version from Debian repositories is Tomcat 8.0.14

Solution is to download from official site and install newest package of Tomcat 8, 8.5, 9 or upgrade to newest version(8.5.x) from jessie-backports

Debian 8

Add to /etc/apt/sources.list

deb  jessie-backports main

Then update and install Tomcat from jessie-backports

sudo apt-get update && sudo apt-get -t jessie-backports install tomcat8

I tried all of the above, nothing worked for me. Then I changed tomcat port numbers both HTTP/1.1 and Tomcat admin port and it got solved.

I see other solutions above worked for the people but it is worth to try this one if any of the above doesn't work.

Thanks everyone!

In our case it turned out that the error happened because we have a custom filter in our application which does HttpServletResponse sendRedirect() to other url.

For some reason, the redirection is not closing the keep-alive status of the connection, hence the timeout exception.

We checked with Tomcat Docs and when we disabled the maxKeepAliveRequests by setting it's value to 1 and the error stopped showing up.

For now we do not have the actual solution to the error.

If you don't want to upgrade your tomcat, Add this line in your catalina.properties

tomcat.util.http.parser.HttpParser.requestTargetAllow=|{}

It works for me

I had this issue when working on a Java Project in Debian 10 with Tomcat as the application server.

The issue was that the application already had https defined as it's default protocol while I was using http to call the application in the browser. So when I try running the application I get this error in my log file:

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.

I however tried using the https protocol in the browser but it didn't connect throwing the error:

Here's how I solved it:

You need a certificate to setup the https protocol for the application. I first had to create a keystore file for the application, more like a self-signed certificate for the https protocol:

sudo keytool -genkey -keyalg RSA -alias tomcat -keystore /usr/share/tomcat.keystore

Note: You need to have Java installed on the server to be able to do this. Java can be installed using sudo apt install default-jdk.

Next, I added a https Tomcat server connector for the application in the Tomcat server configuration file (/opt/tomcat/conf/server.xml):

sudo nano /opt/tomcat/conf/server.xml

Add the following to the configuration of the application. Notice that the keystore file location and password are specified. Also a port for the https protocol is defined, which is different from the port for the http protocol:

<Connector protocol="org.apache.coyote.http11.Http11Protocol"
           port="8443" maxThreads="200" scheme="https"
           secure="true" SSLEnabled="true"
           keystoreFile="/usr/share/tomcat.keystore"
           keystorePass="my-password"
           clientAuth="false" sslProtocol="TLS"
           URIEncoding="UTF-8"
           compression="force"
           compressableMimeType="text/html,text/xml,text/plain,text/javascript,text/css"/>

So the full server configuration for the application looked liked this in the Tomcat server configuration file (/opt/tomcat/conf/server.xml):

<Service name="my-application">
  <Connector protocol="org.apache.coyote.http11.Http11Protocol"
             port="8443" maxThreads="200" scheme="https"
             secure="true" SSLEnabled="true"
             keystoreFile="/usr/share/tomcat.keystore"
             keystorePass="my-password"
             clientAuth="false" sslProtocol="TLS"
             URIEncoding="UTF-8"
             compression="force"
             compressableMimeType="text/html,text/xml,text/plain,text/javascript,text/css"/>

  <Connector port="8009" protocol="HTTP/1.1"
             connectionTimeout="20000"
             redirectPort="8443" />

  <Engine name="my-application" defaultHost="localhost">
     <Realm className="org.apache.catalina.realm.LockOutRealm">
        <Realm className="org.apache.catalina.realm.UserDatabaseRealm"
             resourceName="UserDatabase"/>
    </Realm>

    <Host name="localhost"  appBase="webapps"
          unpackWARs="true" autoDeploy="true">

        <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
             prefix="localhost_access_log" suffix=".txt"
             pattern="%h %l %u %t &quot;%r&quot; %s %b" />

    </Host>
  </Engine>
</Service>

This time when I tried accessing the application from the browser using:

In my case it was:

https:35.123.45.6:8443

it worked fine. Although, I had to accept a warning which added a security exception for the website since the certificate used is a self-signed one.

That's all.

I hope this helps