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/* | ||
Package event contains functionality related to APM event extraction from traces. | ||
APM Events constitute the core of Datadog's Trace Search functionality. These are, in a nutshell, individual spans | ||
containing important information (but not full trace tree) about an execution and which can therefore be sampled at a | ||
different rate (retaining greater cardinality than that of complete traces). Furthermore, all information in APM events | ||
can be indexed, allowing for very flexible searching. | ||
For instance, consider a web server. The top-level span on traces from this web server likely contains interesting | ||
things such as customer/user id, IPs, HTTP tags, HTTP endpoint, among others. By extracting this top level span from | ||
each trace, converting it into an APM event and feeding it into trace search, you can potentially search and aggregate | ||
this information for all requests arriving at your web server. You couldn't do the same thing with traces because these | ||
capture entire execution trees which are much more expensive to process and store and are therefore heavily sampled. | ||
Of course, if the trace from which APM events were extracted also survives sampling, you can easily see the execution | ||
tree associated with a particular APM event as this link is kept throughout the entire processing pipeline. | ||
*/ | ||
// Package event contains functionality related to APM event extraction from traces. | ||
// | ||
// APM Events constitute the core of Datadog's Trace Search functionality. These are, in a nutshell, individual spans | ||
// containing important information (but not full trace tree) about an execution and which can therefore be sampled at a | ||
// different rate (retaining greater cardinality than that of complete traces). Furthermore, all information in APM events | ||
// can be indexed, allowing for very flexible searching. | ||
// | ||
// For instance, consider a web server. The top-level span on traces from this web server likely contains interesting | ||
// things such as customer/user id, IPs, HTTP tags, HTTP endpoint, among others. By extracting this top level span from | ||
// each trace, converting it into an APM event and feeding it into trace search, you can potentially search and aggregate | ||
// this information for all requests arriving at your web server. You couldn't do the same thing with traces because these | ||
// capture entire execution trees which are much more expensive to process and store and are therefore heavily sampled. | ||
// | ||
// Of course, if the trace from which APM events were extracted also survives sampling, you can easily see the execution | ||
// tree associated with a particular APM event as this link is kept throughout the entire processing pipeline. | ||
package event |