Log monitoring and searching service

Hi Everyone

I am planning to build a log monitoring and searching service.
IT will have the following functionality
1.log ingestion using grok parser
2. search log using LUCENE query language
3. Alerting solution which will parse the log message and look for prespecified rule expression to be to ture. When the expression evaluation is true it will alert people of the event. e.g.
log
122001:Bob.Davis@microsoft.com
grok
%{NUMBER:zipcode:int}:%{CUSTOMEMAIL:email}
alert expression
email.Contains(\"Boby\")
when email contains bob it will send alerts

Whats your thought on this any replay is appreciated.