2.2. Kubernetes density test report¶

Abstract:	This document is the report for Kubernetes density testing

2.2.1. Environment description¶

This report is collected on the hardware described in Intel-Mirantis Performance-Team Lab #1.

2.2.1.1. Software¶

Kubernetes is installed using Kargo deployment tool on Ubuntu 16.04.1.

Node roles:

node1: minion+master+etcd
node2: minion+master+etcd
node3: minion+etcd
node4: minion

Software versions (test case #1):

OS: Ubuntu 16.04.1 LTS (Xenial Xerus)
Kernel: 4.4.0-47
Docker: 1.12.1
Kubernetes: 1.4.3

Software versions (test case #2):

OS: Ubuntu 16.04.1 LTS (Xenial Xerus)
Kernel: 4.4.0-36
Docker: 1.13.1
Kubernetes: 1.5.3

2.2.2. Reports¶

2.2.2.1. Test Case #1: Maximum pods per node¶

Pod startup time is measured with help of MMM(MySQL/Master/Minions) testing suite. To schedule all pods on a single node the original replication controller for minions is updated with scheduler hint. To do this add the following lines into template’s spec section:

nodeSelector:
  kubernetes.io/hostname: node4

Pod status from Kubernetes point of view is retrieved from kubectl tool. The process is automated with kubectl_mon.py, which produces output in CSV format. Charts are created by pod_stats.py script.

Every measurement starts with empty namespace. Then Kubernetes replication controller is created with specified number of pods. We collect pod’s report time and kubectl stats. The summary data is presented below.

POD stats¶
POD_COUNT	POD_FIRST_REPORT, s	KUBECTL_RUN, s	KUBECTL_TERMINATE, s
50	12	44	30
100	27	131	87
200	61	450	153
400	208	∞ (not finished)	390

2.2.2.1.1. Detailed Stats¶

2.2.2.1.1.1. 50 pods¶

Start replication controller with 50 pods

Terminate replication controller with 50 pods

2.2.2.1.1.2. 100 pods¶

Start replication controller with 100 pods

Terminate replication controller with 100 pods

2.2.2.1.1.3. 200 pods¶

Start replication controller with 200 pods

Terminate replication controller with 200 pods

2.2.2.1.1.4. 400 pods¶

Start replication controller with 400 pods.

Note: In this experiment all pods successfully reported, however from Kubernetes API point of view less than 60 pods were in running state. The number of pods reported as running was slowly increasing over the time, but the speed was very low to treat the process as succeed.

Terminate replication controller with 400 pods.

2.2.2.1.1.5. Scale by 100 pods steps¶

In this experiment we scale replication controller up by steps of 100 pods. Scaling process is invoked after all pods are reported as running. On step 3 (201-300 pods) the process has become significantly slower and we’ve started scaling replication controller down. The full cycle is visualized below.

System metrics from API nodes and minion are below

Full Kubernetes stats are available online.

2.2.2.2. Test Case #2: Measure Kubelet capacity¶

Pod startup time is measured with help of MMM(MySQL/Master/Minions) testing suite. Original code was updated. We added automatic creation of charts with pod’s status, when pod startup (or down). To schedule all pods on a single node the original replication controller for minions is updated with scheduler hint. To do this add the following lines into template’s spec section:

nodeSelector:
  kubernetes.io/hostname: <node>

Pod status from Kubernetes point of view is retrieved from kubectl tool. The process is automated with kubectl_mon_v2.py, which collects information about pod’s status and sends to database. Charts are created by updated MMM(MySQL/Master/Minions) testing suite.

Every measurement starts with empty namespace. Then Kubernetes replication controller is created with specified number of pods. We collect pod’s report time and kubectl stats. The summary data is presented below.

POD stats¶
POD_COUNT	NODE_COUNT	POD_FIRST_REPORT, s	KUBECTL_RUN, s	KUBECTL_TERMINATE, s
50	50	197	290	289
100	50	415	597	577
200	50	952	1218	1154
50	100	381	425	536
100	100	788	2093 (with errors)	1076
200	100	2653	3838 (not finished)	3001 (not finished)
50	200	970	1256	1032
100	200	1632	3225	2248
200	200	7098 (6.5% lost)	8075 (not finished)	∞ (not finished)
50	400	1823	2667 (with errors)	2038
100	400	7582	8262 (with errors)	5200
400	50	9607	∞ (not finished)	∞ (not finished)