Update README.rst

Author: wojciech12

demo/README.rst

@@ -1,7 +1,127 @@
 
-Related
--------
+=============
+RED in Python
+=============
 
+How-to
+======
+
+1. Start the appliction, prometheus, alertmanager, and grafana with docker-compose:
+
+   ::
+
+     make docker_build
+     make start
+
+2. Access the services:
+
+   - 8080 - our application
+   - 9090 - prometheus webgui
+   - 9093 - alertmanager
+   - 3000 - grafana
+
+2. Single calls, see targets with prefix *srv_* in `<Makefile>`_
+
+3. Generate trafic (open grafana dashboard to see the metrics):
+
+   ::
+
+     make srv_wrk_random
+
+4. Questions:
+
+   - What can we learn from the graphs?
+   - Can we say sth about out random calls?
+   - Naming? Is it good?
+
+Modifing the default configuration
+==================================
+
+Docker-compose mounts all configuration from the git repo. You can change it locally on your laptop.
+
+1. To reload prometheus configuration after changes:
+
+   ::
+
+     make prometheus_reload_config
+
+2. To reload grafana configuration, restart the grafana docker:
+
+   ::
+
+     docker restart talk-wrocpy-prom-flask_grafana_1
+
+Development
+===========
+    
+- start the app and prometheus stack with docker-compose:
+
+  ::
+  
+    make start
+
+- check the Makefile for example of calls
+
+- to use the traffic generator, you need to install first *wrk*:
+
+  ::
+
+    make srv_wrk_random
+
+Example of Prometheus Queries
+=============================
+
+- simple:
+
+  ::
+
+    order_mgmt_duration_seconds_sum{status_code='200'}
+
+  ::
+
+    order_mgmt_duration_seconds_sum{job=~".*"}
+    or
+    order_mgmt_database_duration_seconds_sum{job=~".*"}
+    or
+    order_mgmt_audit_duration_seconds_sum{job=~".*"}
+
+- based on weave blog (https://www.weave.works/blog/of-metrics-and-middleware/):
+
+  - QPS:
+
+    ::
+
+      sum(irate(order_mgmt_duration_seconds_count{job=~".*"}[1m])) by (status_code)
+
+  - will give you the rate of requests returning 500s:
+
+    ::
+
+      sum(irate(order_mgmt_duration_seconds_count{job=~".*", status_code=~"5.."}[1m]))
+
+  - by status_code:
+
+    ::
+
+      sum(irate(order_mgmt_duration_seconds_count{job=~".*"}[1m])) by (status_code)
+
+  - 500s:
+
+    ::
+
+      sum(irate(order_mgmt_duration_seconds_count{job=~".*", status_code=~"5.."}[1m]))
+      
+  - will give you the 5-min moving 99th percentile request latency:
+
+    ::
+
+      histogram_quantile(0.99, sum(rate(order_mgmt_duration_seconds_count{job=~".*",ws="false"}[5m])) by (le))
+
+Related Work
+============
+
+- https://prometheus.io/docs/prometheus/latest/querying/functions/
+- https://www.robustperception.io/combining-alert-conditions/
 - https://github.com/prometheus/jmx_exporter
 - https://www.callicoder.com/spring-boot-actuator/
 - https://blog.kubernauts.io/https-blog-kubernauts-io-monitoring-java-spring-boot-applications-with-prometheus-part-1-c0512f2acd7b