Queries
- Request Header Fields Too Large
  - Problem
  - Solution

Queries

This page presents problems encountered with queries in Presto.

`Request Header Fields Too Large`

Problem

A query may return an error similar to the following example:

1. Error running command: Error starting query at http://localhost:8080/v1/statement
2. returned an invalid response: JsonResponse{statusCode=431, statusMessage=Request
3. Header Fields Too Large, headers={connection=[close], content-length=[74],
4. content-type=[text/html;charset=iso-8859-1]}, hasValue=false}
5. [Error: <h1>Bad Message 431</h1><pre>reason: Request Header Fields Too Large</pre>]

Some examples of how this can happen are:

many session properties have been added to the query
putting a lot of information in clientInfo
large security keys being sent in the session

If such an error happens, increasing the value of http-server.max-request-header-size can help avoid it.

Solution

Edit config.properties for the Presto coordinator, and set the value of the http-server.max-request-header-size configuration property to a larger size. For example:

1. http-server.max-request-header-size=5MB

See http-server.max-request-header-size.