Add Measure, TagKey and View constants for recording HTTP stats (#360)

* Add Measure, TagKeys and Views constants for recording HTTP stats

* minor nit fix

* Remove zero bounds

packages/opencensus-instrumentation-http/src/http-metrics.ts

@@ -0,0 +1,239 @@
+/**
+ * Copyright 2019, OpenCensus Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License'};
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      gRPC://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import {AggregationType, globalStats, MeasureUnit, Stats, View} from '@opencensus/core';
+
+/**
+ * {@link Measure} for the client-side total bytes sent in request body (not
+ * including headers). This is uncompressed bytes.
+ */
+export const HTTP_CLIENT_SENT_BYTES = globalStats.createMeasureInt64(
+    'opencensus.io/http/client/sent_bytes', MeasureUnit.BYTE,
+    'Client-side total bytes sent in request body (uncompressed)');
+
+/**
+ * {@link Measure} for the client-side total bytes received in response
+ * bodies (not including headers but including error responses with bodies).
+ * Should be measured from actual bytes received and read, not the value of
+ * the Content-Length header. This is uncompressed bytes. Responses with no
+ * body should record 0 for this value.
+ */
+export const HTTP_CLIENT_RECEIVED_BYTES = globalStats.createMeasureInt64(
+    'opencensus.io/http/client/received_bytes', MeasureUnit.BYTE,
+    'Client-side total bytes received in response bodies (uncompressed)');
+
+/**
+ * {@link Measure} for the client-side time between first byte of request
+ * headers sent to last byte of response received, or terminal error.
+ */
+export const HTTP_CLIENT_ROUNDTRIP_LATENCY = globalStats.createMeasureDouble(
+    'opencensus.io/http/client/roundtrip_latency', MeasureUnit.MS,
+    'Client-side time between first byte of request headers sent to last byte of response received, or terminal error');
+
+/**
+ * {@link Measure} for the server-side total bytes received in request body
+ * (not including headers). This is uncompressed bytes.
+ */
+export const HTTP_SERVER_RECEIVED_BYTES = globalStats.createMeasureInt64(
+    'opencensus.io/http/server/received_bytes', MeasureUnit.BYTE,
+    'Server-side total bytes received in request body (uncompressed)');
+
+/**
+ * {@link Measure} for the server-side total bytes sent in response bodies
+ * (not including headers but including error responses with bodies). Should
+ * be measured from actual bytes written and sent, not the value of the
+ * Content-Length header. This is uncompressed bytes. Responses with no
+ * body should record 0 for this value.
+ */
+export const HTTP_SERVER_SENT_BYTES = globalStats.createMeasureInt64(
+    'opencensus.io/http/server/sent_bytes', MeasureUnit.BYTE,
+    'Server-side total bytes sent in response bodies (uncompressed)');
+
+/**
+ * {@link Measure} for the server-side time between first byte of request
+ * headers received to last byte of response sent, or terminal error.
+ */
+export const HTTP_SERVER_LATENCY = globalStats.createMeasureDouble(
+    'opencensus.io/http/server/server_latency', MeasureUnit.MS,
+    'Server-side time between first byte of request headers received to last byte of response sent, or terminal error');
+
+/** {@link TagKey} for the value of the client-side HTTP host header. */
+export const HTTP_CLIENT_HOST = {
+  name: 'http_client_host'
+};
+
+/** {@link TagKey} for the value of the server-side HTTP host header. */
+export const HTTP_SERVER_HOST = {
+  name: 'http_server_host'
+};
+
+/**
+ * {@link TagKey} for the numeric client-side HTTP response status code (e.g.
+ * 200, 404, 500). If a transport error occurred and no status code was read,
+ * use "error" as the {@code TagValue}.
+ */
+export const HTTP_CLIENT_STATUS = {
+  name: 'http_client_status'
+};
+
+/**
+ * {@link TagKey} for the numeric server-side HTTP response status code (e.g.
+ * 200, 404, 500). If a transport error occurred and no status code was written
+ * use "error" as the {@code TagValue}.
+ */
+export const HTTP_SERVER_STATUS = {
+  name: 'http_server_status'
+};
+
+/**
+ * {@link TagKey} for the client-side URL path (not including query string) in
+ * the request.
+ */
+export const HTTP_CLIENT_PATH = {
+  name: 'http_client_path'
+};
+
+/**
+ * {@link TagKey} for the server-side URL path (not including query string) in
+ * the request.
+ */
+export const HTTP_SERVER_PATH = {
+  name: 'http_server_path'
+};
+
+/**
+ * {@link TagKey} for the client-side HTTP method of the request, capitalized
+ * (GET, POST, etc.).
+ */
+export const HTTP_CLIENT_METHOD = {
+  name: 'http_client_method'
+};
+
+/**
+ * {@link TagKey} for the server-side HTTP method of the request, capitalized
+ * (GET, POST, etc.).
+ */
+export const HTTP_SERVER_METHOD = {
+  name: 'http_server_method'
+};
+
+/**
+ * {@link TagKey} for the server-side logical route, a pattern that matched the
+ * URL, of a handler that processed the request.
+ */
+export const HTTP_SERVER_ROUTE = {
+  name: 'http_server_route'
+};
+
+const SIZE_DISTRIBUTION: number[] = [
+  1024, 2048, 4096, 16384, 65536, 262144, 1048576, 4194304, 16777216, 67108864,
+  268435456, 1073741824, 4294967296
+];
+
+const LATENCY_DISTRIBUTION: number[] = [
+  1,   2,   3,   4,    5,    6,    8,     10,    13,    16,    20,  25,
+  30,  40,  50,  65,   80,   100,  130,   160,   200,   250,   300, 400,
+  500, 650, 800, 1000, 2000, 5000, 10000, 20000, 50000, 100000
+];
+
+/** {@link View} for count of client-side HTTP requests completed. */
+const HTTP_CLIENT_COMPLETED_COUNT_VIEW = globalStats.createView(
+    'opencensus.io/http/client/completed_count', HTTP_CLIENT_ROUNDTRIP_LATENCY,
+    AggregationType.COUNT, [HTTP_CLIENT_METHOD, HTTP_CLIENT_STATUS],
+    'Count of client-side HTTP requests completed');
+
+/** {@link View} for size distribution of client-side HTTP request body. */
+const HTTP_CLIENT_SENT_BYTES_VIEW = globalStats.createView(
+    'opencensus.io/http/client/sent_bytes', HTTP_CLIENT_SENT_BYTES,
+    AggregationType.DISTRIBUTION, [HTTP_CLIENT_METHOD, HTTP_CLIENT_STATUS],
+    'Size distribution of client-side HTTP request body', SIZE_DISTRIBUTION);
+
+/** {@link View} for size distribution of client-side HTTP response body. */
+const HTTP_CLIENT_RECEIVED_BYTES_VIEW = globalStats.createView(
+    'opencensus.io/http/client/received_bytes', HTTP_CLIENT_RECEIVED_BYTES,
+    AggregationType.DISTRIBUTION, [HTTP_CLIENT_METHOD, HTTP_CLIENT_STATUS],
+    'Size distribution of client-side HTTP response body', SIZE_DISTRIBUTION);
+
+/**
+ * {@link View} for roundtrip latency distribution of client-side HTTP requests.
+ */
+const HTTP_CLIENT_ROUNDTRIP_LATENCY_VIEW = globalStats.createView(
+    'opencensus.io/http/client/roundtrip_latency',
+    HTTP_CLIENT_ROUNDTRIP_LATENCY, AggregationType.DISTRIBUTION,
+    [HTTP_CLIENT_METHOD, HTTP_CLIENT_STATUS],
+    'Roundtrip latency distribution of client-side HTTP requests',
+    LATENCY_DISTRIBUTION);
+
+/** {@link View} for count of server-side HTTP requests serving completed. */
+const HTTP_SERVER_COMPLETED_COUNT_VIEW = globalStats.createView(
+    'opencensus.io/http/server/completed_count', HTTP_SERVER_LATENCY,
+    AggregationType.COUNT,
+    [HTTP_SERVER_METHOD, HTTP_SERVER_ROUTE, HTTP_SERVER_STATUS],
+    'Count of HTTP server-side requests serving completed');
+
+/** {@link View} for size distribution of server-side HTTP request body. */
+const HTTP_SERVER_RECEIVED_BYTES_VIEW = globalStats.createView(
+    'opencensus.io/http/server/received_bytes', HTTP_SERVER_RECEIVED_BYTES,
+    AggregationType.DISTRIBUTION,
+    [HTTP_SERVER_METHOD, HTTP_SERVER_ROUTE, HTTP_SERVER_STATUS],
+    'Size distribution of server-side HTTP request body', SIZE_DISTRIBUTION);
+
+/** {@link View} for size distribution of server-side HTTP response body. */
+const HTTP_SERVER_SENT_BYTES_VIEW = globalStats.createView(
+    'opencensus.io/http/server/sent_bytes', HTTP_SERVER_SENT_BYTES,
+    AggregationType.DISTRIBUTION,
+    [HTTP_SERVER_METHOD, HTTP_SERVER_ROUTE, HTTP_SERVER_STATUS],
+    'Size distribution of server-side HTTP response body', SIZE_DISTRIBUTION);
+
+/**
+ * {@link View} for latency distribution of server-side HTTP requests serving.
+ */
+const HTTP_SERVER_LATENCY_VIEW = globalStats.createView(
+    'opencensus.io/http/server/server_latency', HTTP_SERVER_LATENCY,
+    AggregationType.DISTRIBUTION,
+    [HTTP_SERVER_METHOD, HTTP_SERVER_ROUTE, HTTP_SERVER_STATUS],
+    'Latency distribution of server-side HTTP requests serving',
+    LATENCY_DISTRIBUTION);
+
+const HTTP_BASIC_SERVER_VIEWS: View[] = [
+  HTTP_SERVER_COMPLETED_COUNT_VIEW, HTTP_SERVER_RECEIVED_BYTES_VIEW,
+  HTTP_SERVER_SENT_BYTES_VIEW, HTTP_SERVER_LATENCY_VIEW
+];
+
+const HTTP_BASIC_CLIENT_VIEWS: View[] = [
+  HTTP_CLIENT_COMPLETED_COUNT_VIEW, HTTP_CLIENT_SENT_BYTES_VIEW,
+  HTTP_CLIENT_RECEIVED_BYTES_VIEW, HTTP_CLIENT_ROUNDTRIP_LATENCY_VIEW
+];
+
+/** Register all default views. */
+export function registerAllViews(globalStats: Stats) {
+  registerAllClientViews(globalStats);
+  registerAllServerViews(globalStats);
+}
+
+/** Register all default client views. */
+export function registerAllClientViews(globalStats: Stats) {
+  for (const view of HTTP_BASIC_CLIENT_VIEWS) {
+    globalStats.registerView(view);
+  }
+}
+
+/** Register all default server views. */
+export function registerAllServerViews(globalStats: Stats) {
+  for (const view of HTTP_BASIC_SERVER_VIEWS) {
+    globalStats.registerView(view);
+  }
+}