| Latency Comparison Numbers (~2012) | |
| ---------------------------------- | |
| 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 |
The repository for the assignment is public and Github does not allow the creation of private forks for public repositories.
The correct way of creating a private frok by duplicating the repo is documented here.
For this assignment the commands are:
git clone --bare git@github.com:usi-systems/easytrace.git
I have moved this over to the Tech Interview Cheat Sheet Repo and has been expanded and even has code challenges you can run and practice against!
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L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns
Compress 1K bytes with Zippy ............. 3,000 ns = 3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns = 20 µs
SSD random read ........................ 150,000 ns = 150 µs
Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs
| node { | |
| echo 'Results included as an inline comment exactly how they are returned as of Jenkins 2.121, with $BUILD_NUMBER = 1' | |
| echo 'No quotes, pipeline command in single quotes' | |
| sh 'echo $BUILD_NUMBER' // 1 | |
| echo 'Double quotes are silently dropped' | |
| sh 'echo "$BUILD_NUMBER"' // 1 | |
| echo 'Even escaped with a single backslash they are dropped' | |
| sh 'echo \"$BUILD_NUMBER\"' // 1 | |
| echo 'Using two backslashes, the quotes are preserved' | |
| sh 'echo \\"$BUILD_NUMBER\\"' // "1" |
Whichever route you take to implementing containers, you’ll want to steer clear of common pitfalls that can undermine the efficiency of your Docker stack.
The beauty of containers—and an advantage of containers over virtual machines—is that it is easy to make multiple containers interact with one another in order to compose a complete application. There is no need to run a full application inside a single container. Instead, break your application down as much as possible into discrete services, and distribute services across multiple containers. This maximizes flexibility and reliability.
It is possible to install a complete Linux operating system inside a container. In most cases, however, this is not necessary. If your goal is to host just a single application or part of an application in the container, you need to install only the essential
| # This is an example of the Stack Exchange Tier 1 HAProxy config | |
| # The only things that have been changed from what we are running are: | |
| # 1. User names have been removed | |
| # 2. All Passwords have been remove | |
| # 3. IPs have been changed to use the example/documentation ranges | |
| # 4. Rate limit numbers have been changed to randome numbers, don't read into them | |
| userlist stats-auth | |
| group admin users $admin_user | |
| user $admin_user insecure-password $some_password |
A lot of people land when trying to find out how to calculate CPU usage metric correctly in prometheus, myself included! So I'll post what I eventually ended up using as I think it's still a little difficult trying to tie together all the snippets of info here and elsewhere.
This is specific to k8s and containers that have CPU limits set.
To show CPU usage as a percentage of the limit given to the container, this is the Prometheus query we used to create nice graphs in Grafana:
sum(rate(container_cpu_usage_seconds_total{name!~".*prometheus.*", image!="", container_name!="POD"}[5m])) by (pod_name, container_name) /
| Aerobase | Keycloak | WSO2 Identity Server | Gluu | CAS | OpenAM | Shibboleth IdP | |
|---|---|---|---|---|---|---|---|
| OpenID Connect/OAuth support | yes | yes | yes | yes | yes | yes | third-party |
| Multi-factor authentication | yes | yes | yes | yes | yes | yes | yes |
| Admin UI | yes | yes | yes | yes | yes | yes | no |
| OpenJDK support | yes | yes | yes | yes | no | ||
| Identity brokering | yes | yes | yes | ||||
| Middleware | NGINX, Wildfly | Wildfly, JBOSS | WSO2 Carbon | Jetty, Apache HTTPD | any Java app server | any Java app server | Jetty, Tomc |