This commit does several things to improve the metrics API:
* Move get-client-metrics(-data) functions off of client:
Previously, the `get-client-metrics(-data)`/`.getClientMetrics(Data)`
functions were on the client. This didn't entirely make sense because if two
clients were using the same metric registry, these functions would actually
return metrics data for *all* clients, rather than just for the client the
function was called on. This commit removes these functions and changes the
tests to use the metrics namepsace/Metrics class versions instead, which take
a metric registry return all http-client related metrics on that metric
registry.
* Add a `with-url-and-method` namespace:
Move the timers that have both the url and the method from the `with-url`
namespace to a new `with-url-and-method` namepsace. This better matches the
data structure are returned in and the filtering mechanisms for getting them
back out (discussed below), and also removes a slight chance of having a
conflict with a url timer.
* Add a ClientTimer class:
Add a ClientTimer class that wraps the Timer class and also holds onto the
url, method, or metric id used to create the timer. Use this to add url,
method, metricId to ClientMetricData.
* Change the `getClientMetrics(Data)` methods to return a map of metric
category to an array of timers or timer data:
Previously, the methods for getting http client metrics/metric data out of a
metric registry returned a map of metric name to timer instance or metric
data. However, the metric name was most likely not useful to users, who
probably just want to iterate through the timers/data. This commit makes the
output of these functions more useful by returning arrays of timers/data
sorted into a map indexed by metric category (url, url and method, or metric
id).
* Add `getClientMetricsBy*` methods:
Add `getClientMetrics(Data)ByUrl`, `getClientMetrics(Data)ByUrlAndMethod`, and
`getClientMetrics(Data)ByMetricId` methods (and clojure versions) that allow
for filtering by a specific metric category and return an array of timers or
timer data that match the url, url and method, or metric id specified.
* Remove the filter-builder functions:
Previously, the `get-client-metrics(-data)` functions did filtering by taking
a filter map, and there were filter-builder functions to build these filter
maps. Now that there are separate filtering methods, these filter maps are no
longer used and the filter-builder functions are removed.
This commit adds metrics support to the http client (clojure and java, sync
and async). A metric registry can optionally be passed into the client as a
client option on creation. If a metric registry is present, timers will be
added to time each request.
By default, a timer is added for the URL (stripped of username, password,
query string, and path fragments) and the URL plus the method used for the
request. In addition, a request can include a `metric-id` option, which takes
a tuple of metric ids. If this request option is specified, a timer will be
created for each element of the metric id tuple - thus if the tuple is [:foo
:bar :baz] there will be a foo timer, a foo.bar timer, and a foo.bar.baz
timer.
In addition, each timer has a "MetricType" - currently there is only one
metric type, bytes-read, which is stopped when the full response has been
read. In the future, we may add "response-init" timers that get stopped when
the first byte of the response has been read.
This commit also adds a `get-client-metrics`/`.getClientMetrics` function that
takes a client instance and returns the http client-specific metrics from the
metric registry and a `get-client-metrics-data`/`.getClientMetricsData`
function for clojure and java sync and async clients to get out metrics data
from the client. This function takes a client instance and returns a map of
metric name to a map of metric data (for clojure) or a ClientMetricData object
(for java), both of which include the mean, count, and aggregate for the timer
These `get-client-metrics*`/`.getClientMetrics*` functions also have versions
that take a url, url and method, or metric id to allow for filtering of the
timers/metrics data returned by these functions.
The clojure versions of these functions take a metric filter map. There are
also metric filter builder functions to build up the type of metric filter
desired from a url, a url and method, or a metric id. These will prevent users
from having to know the specifics of how to build a metric themselves; instead
they can use a convenience function.
An empty metric id can be passed in to the filter to return all metric-id
timers.
