2015-07-19 Sunday - MySQL Federated Engine

I'm doing some research this weekend on MySQL's Federated Engine.  This posting is placeholder for collecting various information I find that might be of interest to others.

https://en.wikipedia.org/wiki/MySQL_Federated

http://dev.mysql.com/

http://dev.mysql.com/doc/refman/5.7/en/federated-storage-engine.html

https://dev.mysql.com/doc/refman/5.7/en/federated-usagenotes.html

• A FEDERATED table does not support indexes in the usual sense; because access to the table data is handled remotely, it is actually the remote table that makes use of indexes. This means that, for a query that cannot use any indexes and so requires a full table scan, the server fetches all rows from the remote table and filters them locally. This occurs regardless of any WHERE or LIMIT used with this SELECT statement; these clauses are applied locally to the returned rows
• Queries that fail to use indexes can thus cause poor performance and network overload. In addition, since returned rows must be stored in memory, such a query can also lead to the local server swapping, or even hanging.

http://dba.stackexchange.com/questions/10850/any-disadvantages-to-enabling-federated-storage-engine

http://www.fromdual.com/federated-storage-engine

http://stackoverflow.com/questions/5210309/how-can-i-enable-federated-engine-in-mysql-after-installation

http://www.xaprb.com/blog/2007/01/29/mysqls-federated-storage-engine-part-1/
http://www.xaprb.com/blog/2007/01/31/mysqls-federated-storage-engine-part-2/

http://mihasya.com/blog/abusing-mysql-the-federated-engine/

https://blog.engineyard.com/2012/mysql-table-engines

• "a number of limitations and due to network latency are rarely used...not enabled by default and is no longer maintained by Oracle and it's use is discouraged"

https://mariadb.com/kb/en/mariadb/about-federatedx/

2015-07-11 Saturday - Seattle Code Camp 2015 (9.12.15)

I've submitted an idea for a talk at this year's 2015 Seattle Code Camp, 

entitled: Diagnosing The Patient

"Often when invited into an organization as a consultant, every new environment/situation offers numerous new challenges: symptoms of inefficiencies and performance concerns...that span systems, people, processes, infrastructure, and organizational culture. This talk will focus on sharing lessons learned from years of experience - across many different technical platforms, many different industries - and hopefully provide you with a useful, holistic, conceptual framework to help you quickly assess, diagnose, triage, and begin treatment of the system-as-patient."

2015-07-11 Saturday - DNS configuration

In my normal day-to-day architecture role, I seldom need to perform hands-on System Admin and Network Configuration tasks. However, I need to be more deeply involved in reviewing many aspects of infrastructure and network design details for a current client engagement. So today I'm doing some background reading on DNS configuration as part of a new cloud architecture design effort - and deployment planning.

https://en.wikipedia.org/wiki/Domain_Name_System
https://en.wikipedia.org/wiki/BIND

http://linux-sxs.org/internet_serving/dns.html

http://www.tldp.org/HOWTO/DNS-HOWTO.html#toc5
http://www.tldp.org/HOWTO/DNS-HOWTO-5.html

https://help.ubuntu.com/community/BIND9ServerHowto

https://www.digitalocean.com/community/tutorials/how-to-configure-bind-as-a-caching-or-forwarding-dns-server-on-ubuntu-14-04

http://askubuntu.com/questions/330148/how-do-i-do-a-complete-bind9-dns-server-configuration-with-a-hostname

https://www.howtoforge.com/tutorials/bind/

http://www.linuxhomenetworking.com/wiki/index.php/Quick_HOWTO_:_Ch18_:_Configuring_DNS

http://linuxconfig.org/linux-dns-server-bind-configuration

http://www.firewall.cx/linux-knowledgebase-tutorials/system-and-network-services/829-linux-bind-introduction.html

2015-07-04 Saturday - SaaS Performance Tuning Notes

When exploring possible SaaS performance issues, there are a couple of possible questions/concerns that might be worth examining as possible contributing factors:

• Is there possible saturation of server CPU % utilization?
• Is there possible saturation of server Memory % utilization?
• Is there possible saturation of server Disk % utilization?
• Is there possible saturation of the available network bandwidth?
• Check the NIC % utilization on all servers, particularly for the database
• What is the average response time within the data center network?
• Is there possible database thread starvation occurring?
• Are there inefficient SQL queries excessively consuming resources?
• Does the application leverage any SQL query caching?
• Is there lock contention occurring on database operations?
• Would a Master-Slave configuration help distribute some database I/O 
• Write against Master
• Read from Slave (need to understand latency of Master to Slave replication)
• Is there possible excessive session management overhead being incurred?
• How much data is being stored in session management for an average user?
• Is there possible File I/O contention for read/write of session data files?
• Is there possible excessive overhead being incurred for static content delivery?
• Is static content being served up by the same domain for which cookies are specified?
• If so, cookies will be sent for each GET of a static content file

AppDynamics.com can be instrumental in helping isolate problems - as well as additional monitoring tools (e.g. such as Ganglia, SolarWinds, etc.)

In a recent experiment, moving two static content files to an externally hosted Content Delivery Network (CDN) appeared to suggest a possible 66% reduction in page load time.

2015-07-04 Saturday - R Programming Language (v3.2.1)

Experimenting today with the newest 2015-06-18 release of the R programming language (3.2.1)
http://www.r-project.org/
http://www.r-bloggers.com/

exploring The R Manuals
http://cran.r-project.org/manuals.html
http://cran.r-project.org/doc/manuals/r-release/R-intro.html

As well as the 3.4.2 StateET for R Eclipse plugin
http://www.walware.de/goto/statet

 ...In the new Eclipse 4.5 Mars release
https://www.eclipse.org/mars/noteworthy/