Logstash - grok multiline - logstash

Question

I tried using multiline in grok filters but its not working properly.
My Logs are
H3|15:55:04:760|exception|not working properly
message:space exception
at line number 25
My conf file is
input { file {
path => "logs/test.log"
start_position => beginning
sincedb_path => "/dev/null"
}}
filter{
multiline {
pattern => "^(\s|[A-Z][a-z]).*"
what => "previous"
}
if [message] =~ /H\d+/{
grok {
match => ["message", "(?m)%{USERNAME:level}\|%{TIME:timestamp}\|%{WORD:method}\|%{GREEDYDATA:error_Message}" ]
}
}
else {
grok {
match => ["message", "(?m)%{GREEDYDATA:error_Message}" ]
}
}
}
output {elasticsearch { host => "localhost" protocol => "http" port => "9200" }}
I am able to process the first line of log file, but second line of log file is not working where I would like to use multiline
Output i would like to have
{
"#timestamp" => "2014-06-19 00:00:00,000"
"path" => "logs/test.log"
"level"=>"H3"
"timestamp"=>15:55:04:760
"method"=>exception
"error_message"=>not working properly
},
{
"#timestamp" => "2014-06-19 00:00:00,000"
"path" => "logs/test.log"
"error_message" => "space exception at line 25"
}
Kindly help me to get required output.

Answer 1

Your multiline config says, "if I find this pattern, keep it with the previous line".
Your pattern "^(\s|[A-Z][a-z]).*" says "either a space, or a capital letter followed by a lowercase letter, then followed by other stuff".
So, " foo" or "California" would match, but "H3" wouldn't.
I would suggest a pattern that matches the start of your multiline expression, and use the 'negate' feature to have all lines that don't match that pattern join to the original line:
filter {
multiline {
pattern => "^[A-Z][0-9]\|"
negate => 'true'
what => 'previous'
}
}
}
This would take the "H3|" line as the beginning, and join all other lines to it. Depending on the range of values at the beginning of the line, you may need to edit the regexp.