I have logstash and collectd set up such that collectd reports to logstash. This is working fine, except that I get a bunch of metrics for the same timestamp. Is there a way to get the data such that instead of {ts: x, type:metric1, value:value1, ...}, {ts: x, type:metric2, value:value2, ...} ..., I get something like {ts: x, type1:metric1, value1:value1, type2:metric2, value2:value2, ...}? In a sense, aggregate data for a particular metric per timestamp.
I have a feeling, that you might have a "multiline" filter configured in Logstash configuration file. Multiline filter actually takes all the values which were received in the same time and combines them. Try to turn it off and check what you will get.