jm + cms   11

S3 2017-02-28 outage post-mortem
The Amazon Simple Storage Service (S3) team was debugging an issue causing the S3 billing system to progress more slowly than expected. At 9:37AM PST, an authorized S3 team member using an established playbook executed a command which was intended to remove a small number of servers for one of the S3 subsystems that is used by the S3 billing process. Unfortunately, one of the inputs to the command was entered incorrectly and a larger set of servers was removed than intended. The servers that were inadvertently removed supported two other S3 subsystems.  One of these subsystems, the index subsystem, manages the metadata and location information of all S3 objects in the region. This subsystem is necessary to serve all GET, LIST, PUT, and DELETE requests. The second subsystem, the placement subsystem, manages allocation of new storage and requires the index subsystem to be functioning properly to correctly operate. The placement subsystem is used during PUT requests to allocate storage for new objects. Removing a significant portion of the capacity caused each of these systems to require a full restart. While these subsystems were being restarted, S3 was unable to service requests. Other AWS services in the US-EAST-1 Region that rely on S3 for storage, including the S3 console, Amazon Elastic Compute Cloud (EC2) new instance launches, Amazon Elastic Block Store (EBS) volumes (when data was needed from a S3 snapshot), and AWS Lambda were also impacted while the S3 APIs were unavailable.  
s3  postmortem  aws  post-mortem  outages  cms  ops 
28 days ago by jm
Why Static Website Generators Are The Next Big Thing
Now _this_ makes me feel old. Alternative title: "why static website generators have been a good idea since WebMake, 15 years ago".

WebMake does pretty well on the checklist of "key features of the modern static website generator", which are:

1. Templating (check);
2. Markdown support (well, EtText, which predated Markdown by several years);
3. Metadata (check); and
4. Javascript asset pipeline (didn't support this one, since complex front-end DHTML JS wasn't really a thing at the turn of the century. But I would have if it had ;).

So I guess I was on the right track!
web  html  history  webmake  static-sites  bake-dont-fry  site-generators  cms 
november 2015 by jm
Cassandra moving to using G1 as the default recommended GC implementation
This is a big indicator that G1 is ready for primetime. CMS has long been the go-to GC for production usage, but requires careful, complex hand-tuning -- if G1 is getting to a stage where it's just a case of giving it enough RAM, that'd be great.

Also, looks like it'll be the JDK9 default: https://twitter.com/shipilev/status/593175793255219200
cassandra  tuning  ops  g1gc  cms  gc  java  jvm  production  performance  memory 
april 2015 by jm
Squarespace
Nice, simple "build a website" platform. Keeping this one bookmarked for the next time someone non-techie asks me for the simplest way to do just that (thanks for the tip, Oisin)
via:oisin  blog  cms  design  hosting  web-design  web  websites 
april 2015 by jm
Optimizing Java CMS garbage collections, its difficulties, and using JTune as a solution | LinkedIn Engineering
I like the sound of this -- automated Java CMS GC tuning, kind of like a free version of JClarity's Censum (via Miguel Ángel Pastor)
java  jvm  tuning  gc  cms  linkedin  performance  ops 
april 2015 by jm
Impact of large primitive arrays (BLOBS) on JVM Garbage Collection
some nice graphs and data on CMS performance, with/without -XX:ParGCCardsPerStrideChunk
cms  java  jvm  performance  optimization  tuning  off-heap-storage  memory 
march 2014 by jm
What drives JVM full GC duration
Interesting empirical results using JDK 7u21:
Full GC duration depends on the number of objects allocated and the locality of their references. It does not depend that much on actual heap size.


Reference locality has a surprisingly high effect.
java  jvm  data  gc  tuning  performance  cms  g1 
october 2013 by jm
Tuning and benchmarking Java 7's Garbage Collectors: Default, CMS and G1
Rudiger Moller runs through a typical GC-tuning session, in exhaustive detail
java  gc  tuning  jvm  cms  g1  ops 
july 2013 by jm
Java Garbage Collection Distilled
Martin Thompson lays it out:
Serial, Parallel, Concurrent, CMS, G1, Young Gen, New Gen, Old Gen, Perm Gen, Eden, Tenured, Survivor Spaces, Safepoints, and the hundreds of JVM start-up flags. Does this all baffle you when trying to tune the garbage collector while trying to get the required throughput and latency from your Java application? If it does then don’t worry, you are not alone. Documentation describing garbage collection feels like man pages for an aircraft. Every knob and dial is detailed and explained but nowhere can you find a guide on how to fly. This article will attempt to explain the tradeoffs when choosing and tuning garbage collection algorithms for a particular workload.
gc  java  garbage-collection  coding  cms  g1  jvm  optimization 
june 2013 by jm
Everything I Ever Learned About JVM Performance Tuning @Twitter
presentation by Attila Szegedi of Twitter from last year. Some good tips here, well-presented
tuning  jvm  java  gc  cms  presentations  slides  twitter 
december 2012 by jm
flogr
'shows your pictures from flickr in a customizable photo portfolio interface which includes a main photo page with EXIF details and flickr user comments, a customizable thumbnails page of your recent work, a slideshow component to browse through thumbnails, a tag cloud page, and an about page that shows your flickr user profile. With flogr you can control which photos are shown by specifying the flickr tag(s) to include so you can show only your best photographs if you choose. Flogr is powered by PHP, MySQL (optional), and Flickr.' excellent! via yoz
via:yoz  flickr  photos  web  cms  php  blogging  photoblog  gallery  slideshow  flogr  from delicious
november 2009 by jm

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