1. A method executed by one or more data processing devices, comprising: receiving log data; receiving a first parsing rule and a second parsing rule, the first parsing rule and second parsing rule configured to extract a named value based on the received log data; identifying a conflict between the first parsing rule and the second parsing rule; resolving the conflict; and extracting the named value using a combination of the first parsing rule and the second parsing rule.
3. The method of claim 1 , where receiving the first parsing rule includes receiving a tag and an expression, the tag including a name corresponding to the value, the expression including a pattern for identifying the value corresponding to the name.