1. Monitoring and
Log Management for
Docker Swarm and Kubernetes
Stefan Thies Sematext Group, Inc.

2. Sematext & I
Logsene
SPM
log
s
metric
s
Docker Agent
#nodejs

3. Agenda
•What is
• Centralized Log Management + Performance Monitoring
• Kubernetes / Swarm
•Container Logs
•Container Metrics
•Example: #Swarm3k Monitoring
•Summary

4. Centralized Log Management
Logagen
t
Logagen
t

5. Centralized Monitoring
Expose
Metrics
Collect
Metrics
Ship Metrics
Store
Metrics
Aggregate
Metrics
Visualize
Metrics
• Correlation
with Logs
Anomaly
Detection
Alerting
Server +
App /
Container
Configuration
Monitoring
Agents
Time
Series
Database
Dashboard
Tools,
Alerting Tools,
ChatOps Tools

6. https://sematext.com/blog/2016/07/19/open-source-docker-monitoring-loggi
ng/

7. Orchestration
Container
POD
Node Node 1
POD 1
Namespace
ns1
Kibana Elasticsearch
POD 2
Namespace
ns2
Redis
Services (proxy)
Replication
Controllers
DaemonSets
3
HorizontalPod
Autoscaler

8. Kubernetes Dashboard / Heapster
•Current status
•Shows basic resource usage
for workloads (Pod)
•Simple logs view
•Heapster is required for
autoscaling features

9. Orchestration
Container
Stacks
Nodes Node 1
ELK
(compose, app
bundle)
Kibana 1 Elasticsearch 1
Redis
(service)
redis1
3
Node 2
ELK
Elasticsearch
2
Elasticsearch
3

10. Kubernetes != Swarm
•Common base is Docker
• Docker Logs & Metrics
• Docker API

11. Container Logs

12. Docker Logging Drivers
Docker
json-file (default) Files
journald (CoreOS) System journal
Syslog
TCP
UDP
Fluentd TCP
$plunk TCP
Gelf
Centralized
Log Management
Local Log Shipper

13. Docker logs
Containers (should) log to stdout/stderr !!!
docker logs container_id
docker logs container_name
Docker
API
Docker
client
Container
logs

14. Fun with Docker logging drivers
$ docker run --log-driver=syslog
--log-opt syslog-address=udp://$HOSTNAME:514
--log-opt tag=„{{.ImageName}}#{{.Name}}#{{.ID}}"
-p 9003:80 –name nginx1 -d nginx
$ docker logs nginx 1
"logs" command is supported only for "json-file"
and "journald" logging drivers (got: syslog)
Add
Context!

15. More fun with TCP logging drivers!
docker run --log-driver=syslog --log-opt
syslog-address=tcp://127.0.0.1:514 --log-opt
tag="{{.ImageName}}#{{.Name}}#{{.ID}}" -p
9004:80 -d nginx
docker: Error response from daemon: Failed to
initialize logging driver: dial tcp
127.0.0.1:514: getsockopt: connection refused.

16. Fix it – run syslog server first!
docker run -d -p 514:514 factorish/syslog -t tcp
docker run –logging-driver=syslog … nginx
curl localhost:9004
docker logs syslog
==> syslog listening on tcp
<30>Nov 17 18:23:43
nginx#nginx1#afebdfff0eed[1710]: 172.17.0.1 - -
[17/Nov/2016:18:23:43 +0000] "GET / HTTP/1.1" 200
612 "-" "curl/7.49.1" "-"

17. Is UDP
better?

18. Alternatives?
Docker
Log files
json-file or
journald
API
Agent
Remote
Log Storage
Disk
Buffer
Docker API
provides
the most complete
information!
Reliable networks and
backend services?
Better buffer & retransmit
in case of failure!
Attach metadata
to logs/metrics or
route data to
different servers
or indices?
“docker logs”
works & logs are
stored on local
disk!
Centralize search,
analytics, alerts,
access permissions
Parse logs

19. Automatic tagging of logs, metrics, events
• Automatic tagging of log / metrics with
• Docker
• Container Name / ID
• Image Name / ID
• Labels / Environment
• Hostname / IP
• Kubernetes
• Namespace, Pod Name , UID
• Swarm
• Swarm Service Name , ID, Compose Project, Container # (scale)
• Single collector for logs, metrics, events, metadata
• Base for correlation and visualisation

20. Container Metrics Collection

21. Collection

22. Metric collection via Docker API

23. Smart monitoring agent - all in one
Docker
API
Agent
Remote
Storage
Disk
Buffer
Docker API
provides
Labels, Metrics,
Logs, Events …
Reliable networks and
backend services?
Better buffer & retransmit
in case of failure!
Auto-tagging
using container
labels.
Discovery of
services Centralize logs, metrics,
analytics, alerts, access
permissions
Metrics,
Logs,
Events

24. Integrate application monitoring in the stack
-Custom images
- add/remove
app with all req. options
-Start monitoring,
reading config from etcd
App
Config to expose
metrics
App Monitor
Configured for App
Container
Service Discovery
etcd
consul

25. Auto Discovery via Docker API and Labels?
App Container
config to expose
metrics
App MonitorDocker Monitor
run
discovery
Docker
Automatic
run

26. Key Container Metrics

27. Node Storage
•Good kids clean up their rooms. Good Docker ops clean up their
disks by removing unused containers & images.

28. Number of containers per host
•Verify deployment strategies

29. CPU quota per container

30. Container memory and OOM counter

31. Docker Events

32. Swarm Task Status

33. Limit container resources for your apps!
•Set CPU quotas cpu-quota=6000
•Limit Memory and configure App in container to the same limits!
m 512mb
•Disable Swap: memory-swap=0
•To limit a Docker container from eating all your disk IO use
e.g. device-write-bps /dev/sda:1mb

34. Automatic Deployment of monitoring agents
• One command to run a service
on each node joining the cluster
• Kubernetes:
• DaemonSet creates a pod per
node
kubectl create -f
sematext-agent.yml
• Swarm:
• Global Service docker
service create –mode
global ...

35. Swarm3k Monitoring

36. Swarm3k Requirements
•Monitoring
• Host metrics
• Container metrics
• Docker Events
• Task Monitoring
•Collect Container Logs: Task Errors only
•3000+ Nodes (actual: 4.7k)
•150.000 (actual: 60k)
•Duration 8 hours – 28 GB data collected
•Public/shared Dashboard for the community

37. Pre-flight test with 500 nodes
•60.000 containers deployed in less than 5 minutes!

38. Swarm3k in one picture

39. Limits in visualisation
Missing Labels to
group hosts or
containers

40. Summary
•Setup of Monitoring & Logging is complex in dynamic environments
•Kubernetes != Swarm (yet). Common base: Docker Containers
•Smart Agents to collect, analyze, aggregate metrics, events and logs
• Auto discovery of containers for data collection
• Use metadata tag metrics & logs as base for correlation and visualization
• Integrate monitoring in application stacks for app specific metrics
• Auto Discovery of services and automatic configuration for application level
monitoring

41. We are engineers!
We develop DevOps tools!
We are DevOps people!
We do fun stuff ;)
join us
http://sematext.com/jobs
is hiring!

42. Thank you for listening! Get in touch!
Stefan Thies
stefan.thies@sematext.com
@seti321
http://sematext.com
@sematext
join us
http://sematext.com/jobs
Come talk to us
at the booth