Monthly Archives: April 2016

Stack Overflow: The Architecture – 2016 Edition


So what’s changed in the last 2 years? Besides replacing some servers and network gear, not much. Here’s a top-level list of hardware that runs the sites today (noting what’s different since 2013):

  • 4 Microsoft SQL Servers (new hardware for 2 of them)

  • 11 IIS Web Servers (new hardware)

  • 2 Redis Servers (new hardware)

  • 3 Tag Engine servers (new hardware for 2 of the 3)

  • 3 Elasticsearch servers (same)

  • 4 HAProxy Load Balancers (added 2 to support CloudFlare)

  • 2 Networks (each a Nexus 5596 Core + 2232TM Fabric Extenders, upgraded to 10Gbps everywhere)

  • 2 Fortinet 800C Firewalls (replaced Cisco 5525-X ASAs)

  • 2 Cisco ASR-1001 Routers (replaced Cisco 3945 Routers)

  • 2 Cisco ASR-1001-x Routers (new!)


Full article

mysqldump > unknown table engine ‘PERFORMANCE_SCHEMA’

Lets simply force mysqldump to ignore all performance_schema tables.

# mysqldump -u <username> -p <password> --all-databases > /root/mysql.full.dump --ignore-table=performance_schema.cond_instances --ignore-table=performance_schema.events_waits_current --ignore-table=performance_schema.cond_instances --ignore-table=performance_schema.events_waits_history --ignore-table=performance_schema.events_waits_history_long  --ignore-table=performance_schema.events_waits_summary_by_instance --ignore-table=performance_schema.events_waits_summary_by_thread_by_event_name --ignore-table=performance_schema.events_waits_summary_global_by_event_name --ignore-table=performance_schema.file_instances --ignore-table=performance_schema.file_summary_by_event_name  --ignore-table=performance_schema.file_summary_by_instance  --ignore-table=performance_schema.mutex_instances --ignore-table=performance_schema.performance_timers  --ignore-table=performance_schema.rwlock_instances --ignore-table=performance_schema.setup_consumers --ignore-table=performance_schema.setup_instruments --ignore-table=performance_schema.setup_timers --ignore-table=performance_schema.threads

But remember!
An error is always an error!
This solution isn’t 100% recommended!

mysql – Can’t create/write to file ‘/tmp/


[email protected]:~# mysqldump -u root --all-databases > colo18.sql
mysqldump: Couldn't execute 'show fields from `crongal`': Can't create/write to file '/tmp/#sql_b8c_0.MYI' (Errcode: 13) (1)

Lets set the proper permissions to /temp

sudo chmod 1777 /tmp

It will solve the issue.