Logstash exclude_keys

nput file:kvoptions.log
{“Name”:“admin”,“ConfigurationObjectType”:“ExecutionGroup”}

Configuration file:
input
{
file
{
path => “/home/murugar/Documents/kvoptions.log”
type => “file”
start_position => “beginning”
sincedb_path=> “/dev/null”

}
}
filter
{
grok
{
match => [“message”,"%{GREEDYDATA:msg}"]
}

kv
{
source => "msg"
field_split => ",\{\}"
value_split => ":"
exclude_keys => ["ConfigurationObjectType"]
}

}

output
{

stdout
{
codec => rubydebug
}
}

Obtained Ouput
{
“message” => “{“Name”:“admin”,“ConfigurationObjectType”:“ExecutionGroup”}”,
@version” => “1”,
@timestamp” => “2018-07-18T01:43:30.128Z”,
“path” => “/home/murugar/Documents/kvoptions.log”,
“host” => “0.0.0.0”,
“type” => “file”,
“msg” => “{“Name”:“admin”,“ConfigurationObjectType”:“ExecutionGroup”}”,
““Name”” => “admin”,
““ConfigurationObjectType”” => “ExecutionGroup”
}

Expected Ouput:

{
{
“message” => “{“Name”:“admin”,“ConfigurationObjectType”:“ExecutionGroup”}”,
@version” => “1”,
@timestamp” => “2018-07-18T01:43:30.128Z”,
“path” => “/home/murugar/Documents/kvoptions.log”,
“host” => “0.0.0.0”,
“type” => “file”,
“msg” => “{“Name”:“admin”,“ConfigurationObjectType”:“ExecutionGroup”}”,
““Name”” => “admin”,

}

}

In other word, the last bolded line should not appear. Why isnt exclude_keys working?