tennix

Direct links to free Springer books (pdf versions)

Graduate texts in mathematics

duplicates = multiple editions

A Classical Introduction to Modern Number Theory, Kenneth Ireland Michael Rosen

A Classical Introduction to Modern Number Theory, Kenneth Ireland Michael Rosen

tennix

Latency Comparison Numbers
--------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

tennix

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: disk-benchmark
spec:
  replicas: 1
  selector:
    matchLabels:
      app: disk-benchmark
  serviceName: disk-benchmark

tennix

# This file is copied from https://github.com/kubernetes-incubator/external-storage/blob/master/local-volume/provisioner/deployment/kubernetes/gce/provisioner_generated_gce_ssd_count.yaml
# but namespace is changed to `kube-system` and add a disk-remounter init container

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: "local-scsi"
provisioner: "kubernetes.io/no-provisioner"
volumeBindingMode: "WaitForFirstConsumer"
---

tennix

apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: startup-script
  namespace: kube-system
  labels:
    app: startup-script
spec:
  template:
    metadata:

tennix

apiVersion: apps/v1
kind: Deployment
metadata:
  name: web
spec:
  selector:
    matchLabels:
      app: nginx
  replicas: 3
  template:

tennix

#!/usr/bin/env python
import json
from jinja2 import Template
# git clone https://github.com/pingcap/tidb-docker-compose
# cd tidb-docker-compose
# git clone https://github.com/tennix/grafonnet-lib -b table
# python dashboard-to-jsonnet.py > pd.jsonnet
# jsonnet -J grafonnet-lib pd.jsonnet > config/dashboards/generated-pd.json
with open('config/dashboards/pd.json', 'r') as f:
    data = json.load(f)

tennix

To verify if the DNS service is normal in a Kubernetes cluster. We can deploy a simple service to diagnose this:

$ kubectl apply -f nginx.yaml
$ kubectl exec -it web-0 sh # enter web-0 pod to resolve the other two pods domain name.
/ # nslookup web-1.nginx
/ # nslookup web-2 nginx

tennix

apiVersion: v1
kind: ConfigMap
metadata:
  name: fluent-bit-config
  labels:
    app: fluent-bit
data:
  fluent-bit-service.conf: |-
    [SERVICE]
        Flush        1