Month: November 2013

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Stabilized Footage of the JFK Assassination Is Unsettlingly Real

When it’s bouncing around and playing back at a jittery 18 frames per second, the infamous Zapruder footage of John F. Kennedy’s assassination feels almost unreal. But when it’s stabilized with additional interpolated frames bringing it to a steady 30 frames per second (like we’re used to seeing on TV) it suddenly becomes much more real.

via Gizmodo
Stabilized Footage of the JFK Assassination Is Unsettlingly Real

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7 Productivity Boosting Keyboard Shortcuts Every Mac User Should Know

We love our keyboard shortcuts, as they help us get around our computers much faster every day. Here are seven you may not know about on the Mac that can boost your productivity by making navigation easier and performing tasks faster.

Check out the video above for a demonstration of each shortcut, or a list below for our choices:

  • Command+Shift+A/U/D: These three-in-one shortcuts take you to the Applications, Utilities, and Desktop folders (respectively) when in the Finder. Because you’ll need to get to each relatively often, this key command can save you quite a bit of time.
  • Command+1/2/3/4: When you need to change views in the finder, you don’t have to bother with your mouse. 1 will get you icon view, 2 list view, 3 column view, and 4 cover flow.
  • Command+Option+I: When you need info on multiple files, just select them and execute this key command. You’ll get an info panel about everything currently selected.
  • Command+Shift+4 and Space: When you press Command+Shift+4 you get to take a screenshot of a specific area on the screen. If you hit the space bar afterwards, however, you can click on any window to get a nice PNG with transparent background of that window.
  • Command+Option+M: Sometimes you end up with too many windows on your desktop and you just want to cut your losses. Minimize them all to the dock with this keyboard shortcut.
  • Command+(Shift)+~: If you’d rather cycle through millions of windows, you can use this key command to do so. Add or remove the shift key to change directions.
  • Command+Option+Space: Most of us know that you can search Spotlight quickly by pressing Command+Space. Add the option key to get a Spotlight search window and get more specific about what you’re trying to find.

OS X has plenty of awesome shortcuts and they certainly don’t stop after seven. These, however, will help you get around your Mac a little bit faster and have similar structures so they’re easy to remember.


via Lifehacker
7 Productivity Boosting Keyboard Shortcuts Every Mac User Should Know

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Upgrading from the earlier MySQL RPM Format to Yum Repos

The packages that are available in the yum repos contain a number of enhancements over the RPM packages that are available from dev.mysql.com.
Norvald blogged on some of these enhancements earlier. Today I wanted to walk through a safe upgrade path, as they are not quite compatible with each-other.
My Existing Installation
To start with, the packages I have installed came from “Red Hat Enterprise Linux 6 / Oracle Linux 6 (x86, 64-bit), RPM Bundle” on dev.mysql.com. You can check which packages you have installed with:
[root@localhost ~]# rpm -qa | grep -i mysql
MySQL-client-5.6.14-1.el6.x86_64
MySQL-embedded-5.6.14-1.el6.x86_64
MySQL-server-5.6.14-1.el6.x86_64
MySQL-shared-5.6.14-1.el6.x86_64
MySQL-devel-5.6.14-1.el6.x86_64
MySQL-test-5.6.14-1.el6.x86_64
MySQL-shared-compat-5.6.14-1.el6.x86_64
Uninstalling and Installing Yum repos
I recommend first running yum update before installing the new repo:
yum update
yum localinstall http://repo.mysql.com/mysql-community-release-el6-3.noarch.rpm
After this step, stop MySQL (note the missing d in the dev.mysql.com packages):
service mysql stop
Now with yum shell it’s possible to uninstall the existing packages (listed in ‘my existing installation’ above) and install the replacement packages from the yum repo in one step:
yum shell
> remove MySQL-client-5.6.14-1.el6 MySQL-embedded-5.6.14-1.el6 MySQL-server-5.6.14-1.el6 MySQL-shared-5.6.14-1.el6 MySQL-devel-5.6.14-1.el6 MySQL-test-5.6.14-1.el6 MySQL-shared-compat-5.6.14-1.el6 > install mysql-community-server
> run
Here was the summary output from my yum session:
============================================================================================================================
Package Arch Version Repository Size
============================================================================================================================
Installing:
mysql-community-server x86_64 5.6.14-3.el6 mysql-community 51 M
Removing:
MySQL-client x86_64 5.6.14-1.el6 @/MySQL-client-5.6.14-1.el6.x86_64 81 M
MySQL-devel x86_64 5.6.14-1.el6 @/MySQL-devel-5.6.14-1.el6.x86_64 19 M
MySQL-embedded x86_64 5.6.14-1.el6 @/MySQL-embedded-5.6.14-1.el6.x86_64 432 M
MySQL-server x86_64 5.6.14-1.el6 @/MySQL-server-5.6.14-1.el6.x86_64 235 M
MySQL-shared x86_64 5.6.14-1.el6 @/MySQL-shared-5.6.14-1.el6.x86_64 8.4 M
MySQL-shared-compat x86_64 5.6.14-1.el6 @/MySQL-shared-compat-5.6.14-1.el6.x86_64 11 M
MySQL-test x86_64 5.6.14-1.el6 @/MySQL-test-5.6.14-1.el6.x86_64 318 M
Installing for dependencies:
mysql-community-client x86_64 5.6.14-3.el6 mysql-community 18 M
mysql-community-common x86_64 5.6.14-3.el6 mysql-community 296 k
mysql-community-libs x86_64 5.6.14-3.el6 mysql-community 1.8 M
Removing for dependencies:
cronie x86_64 1.4.4-7.el6 @anaconda-CentOS-201303020151.x86_64/6.4 166 k
cronie-anacron x86_64 1.4.4-7.el6 @anaconda-CentOS-201303020151.x86_64/6.4 43 k
crontabs noarch 1.10-33.el6 @anaconda-CentOS-201303020151.x86_64/6.4 2.4 k
postfix x86_64 2:2.6.6-2.2.el6_1 @anaconda-CentOS-201303020151.x86_64/6.4 9.7 M
Transaction Summary
============================================================================================================================
Install 4 Package(s)
Remove 11 Package(s)
MySQL should now be installed from the yum packages. You just have two more steps to complete – start it, and configure it on boot:
service mysqld start # note the added ‘d’
chkconfig mysqld on
Still having problems? I recommend heading to the MySQL Forums. There is a section dedicated to Install & Repo help.
via Planet MySQL
Upgrading from the earlier MySQL RPM Format to Yum Repos

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Override Your Hotel Room Thermostat and Set It As Hot or Cold You Like

Hotel room thermometers normally don’t let you adjust the temperature above or below a certain point, which can lead to some pretty warm rooms in the summer time or chilly ones in the winter. If you want more control, here’s how to override your hotel thermometer, put it in "VIP" mode, and tweak it where you like it.

Gary Leff, writing for View from the Wing, shared the video above, which shows you how it’s done. Most hotel wall units (Gary noted that Hilton and Hyatt specifically tend to use this type of thermostat) that you’ll have access to will work this way. The window units on the air conditioner/heaters themselves may be a bit more flexible, but give this a try on your next wall thermometer:

  • Hold down the “display” button
  • While holding that button, press “off”
  • Release off, continue to hold down display, and Press the “up” arrow button
  • Release all buttons

This trick also disables the motion sensors that many hotels use to only keep the heating and cooling system active at all when a guest is in the room—that means that you won’t have to wait for a sweltering room to gradually cool off when you get back from a long day, or wait for an ice cold room to warm up in the winter.

Gary explains that you don’t have to just be quirky about the temperature to use this trick—sometimes hotels try and save money by keeping the room thermostats in a certain range, leading to uncomfortable guests, and in his case, he had a room that got a ton of sunlight that warmed it up in the daytime, making it really hot, even with the thermostat turned down as far as it can go. Either way, the power is yours—to be more comfortable when you travel. Hit the link below to read more—his commenters, both at the link below and his much older post have some similar tricks for other hotel chains that may not use these units, too.

How to Override Your Hotel’s Thermostat Controls and Make it as Cool or Hot As You’d Like | View from the Wing


via Lifehacker
Override Your Hotel Room Thermostat and Set It As Hot or Cold You Like

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What SQL is running MySQL

Using the MySQL 5.6 Performance Schema it is very easy to see what is actually running on your MySQL instance. No more sampling or installing software or worrying about disk I/O performance with techniques like SHOW PROCESSLIST, enabling the general query log or sniffing the TCP/IP stack.
The following SQL is used to give me a quick 60 second view on a running MySQL system of ALL statements executed.
use performance_schema;
update setup_consumers set enabled=’YES’ where name IN (‘events_statements_history’,’events_statements_current’,’statements_digest’);
truncate table events_statements_current; truncate table events_statements_history; truncate table events_statements_summary_by_digest;
do sleep(60);
select now(),(count_star/(select sum(count_star) FROM events_statements_summary_by_digest) * 100) as pct, count_star, left(digest_text,150) as stmt, digest from events_statements_summary_by_digest order by 2 desc;
update setup_consumers set enabled=’NO’ where name IN (‘events_statements_history’,’events_statements_current’,’statements_digest’);
NOTE: These statements are for simple debugging and demonstration purposes. If you want to monitor SQL statements on an ongoing basis, you should not simply truncate tables and globally enable/disable options.
There are four performance schema tables that are applicable for looking at initial SQL analysis.
The events_statements_summary_by_digest table shown below gives as the name suggests a way to summarize all queries into a common query pattern (or digest). This is great to get a picture of volume and frequency of SQL statements.
The events_statements_current shows the currently running SQL statements
The events_statements_history shows the fun, because it provides a *short, default 10 threads* history of the SQL statements that have run in any given thread.
The events_statements_history_long (when enabled) gives you a history of the most recent 10,000 events.
One query can give me a detailed review of the type and frequency of ALL SQL statements run. The ALL is important, because on a slave you also get ALL replication applied events.
mysql> select now(),(count_star/(select sum(count_star) FROM events_statements_summary_by_digest) * 100) as pct, count_star, left(digest_text,150) as stmt, digest from events_statements_summary_by_digest order by 2 desc;
select * from events_statements_current where digest=’ffb6231b78efc022175650d37a837b99’\G
+———————+———+————+——————————————————————————————————————————————————–+———————————-+
| now() | pct | count_star | stmt | digest |
+———————+———+————+——————————————————————————————————————————————————–+———————————-+
| 2013-11-07 18:24:46 | 60.6585 | 7185 | SELECT * FROM `D…..` WHERE `name` = ? | d6399273d75e2348d6d7ea872489a30c |
| 2013-11-07 18:24:46 | 23.4192 | 2774 | SELECT nc . id , nc . name FROM A……………… anc JOIN N……….. nc ON anc . …………_id = nc . id WHERE ……._id = ? | c6e2249eb91767aa09945cbb118adbb3 |
| 2013-11-07 18:24:46 | 5.5298 | 655 | BEGIN | 7519b14a899fd514365211a895f5e833 |
| 2013-11-07 18:24:46 | 4.6180 | 547 | INSERT INTO V…….. VALUES (…) ON DUPLICATE KEY UPDATE v…. = v…. + ? | ffb6231b78efc022175650d37a837b99 |
| 2013-11-07 18:24:46 | 1.0891 | 129 | SELECT COUNT ( * ) FROM T…………… WHERE rule = ? AND ? LIKE concat ( pattern , ? ) | 22d984df583adc9a1ac282239e7629e2 |
| 2013-11-07 18:24:46 | 1.0553 | 125 | SELECT COUNT ( * ) FROM T…………… WHERE rule = ? AND ? LIKE concat ( ? , pattern , ? ) | a8ee43287bb2ee35e2c144c569a8b2de |
| 2013-11-07 18:24:46 | 0.9033 | 107 | INSERT IGNORE INTO `K……` ( `id` , `k……` ) VALUES (…) | 675e32e9eac555f33df240e80305c013 |
| 2013-11-07 18:24:46 | 0.7936 | 94 | SELECT * FROM `K……` WHERE k…… IN (…) | 8aa7dc3b6f729aec61bd8d7dfa5978fa |
| 2013-11-07 18:24:46 | 0.4559 | 54 | SELECT COUNT ( * ) FROM D….. WHERE NAME = ? OR NAME = ? | 1975f53832b0c2506de482898cf1fd37 |
| 2013-11-07 18:24:46 | 0.3208 | 38 | SELECT h . * FROM H…….. h LEFT JOIN H………… ht ON h . id = ht . ……_id WHERE ht . ………_id = ? ORDER BY h . level ASC | ca838db99e40fdeae920f7feae99d19f |
| 2013-11-07 18:24:46 | 0.2702 | 32 | SELECT h . * , ( POW ( ? * ( lat – – ? ) , ? ) + POW ( ? * ( ? – lon ) * COS ( lat / ? ) , ? ) ) AS distance FROM H…….. h FORCE INDEX ( lat ) WHER | cd6e32fc0a20fab32662e2b0a282845c |
| 2013-11-07 18:24:46 | 0.1857 | 22 | SELECT h . * , ( POW ( ? * ( lat – ? ) , ? ) + POW ( ? * ( – ? – lon ) * COS ( lat / ? ) , ? ) ) AS distance FROM H…….. h FORCE INDEX ( lat ) WHER | a7b43944f5811ef36c0ded7e79793536 |
| 2013-11-07 18:24:46 | 0.0760 | 9 | SELECT h . * , ( POW ( ? * ( lat – ? ) , ? ) + POW ( ? * ( ? – lon ) * COS ( lat / ? ) , ? ) ) AS distance FROM H…….. h FORCE INDEX ( lat ) WHERE | 4ccd8b28ae9e87a9c0b372a58ca22af7 |
| 2013-11-07 18:24:46 | 0.0169 | 2 | SELECT * FROM `K……` WHERE k…… IN (?) | 44286e824d922d8e2ba6d993584844fb |
| 2013-11-07 18:24:46 | 0.0084 | 1 | SELECT h . * , ( POW ( ? * ( lat – – ? ) , ? ) + POW ( ? * ( – ? – lon ) * COS ( lat / ? ) , ? ) ) AS distance FROM H…….. h FORCE INDEX ( lat ) WH | 299095227a67d99824af2ba012b81633 |
| 2013-11-07 18:24:46 | 0.0084 | 1 | SELECT * FROM `H……..` WHERE `id` = ? | 2924ea1d925a6e158397406403a63e3a |
| 2013-11-07 18:24:46 | 0.0084 | 1 | SHOW ENGINE INNODB STATUS | 0b04d3acd555401f1cbc479f920b1bac |
| 2013-11-07 18:24:46 | 0.0084 | 1 | DO `sleep` (?) | 3d6e973c2657d0d136bbbdad05e68c7a |
| 2013-11-07 18:24:46 | 0.0084 | 1 | SHOW ENGINE INNODB MUTEX | a031f0e6068cb12c5b7508106687c2cb |
| 2013-11-07 18:24:46 | 0.0084 | 1 | SELECT NOW ( ) , ( `count_star` / ( SELECT SUM ( `count_star` ) FROM `events_statements_summary_by_digest` ) * ? ) AS `pct` , `count_star` , LEFT ( `d | 8a9e990cd85d6c42a2e537d04c8c5910 |
| 2013-11-07 18:24:46 | 0.0084 | 1 | SHOW SLAVE STATUS | d2a0ffb1232f2704cef785f030306603 |
| 2013-11-07 18:24:46 | 0.0084 | 1 | TRUNCATE TABLE `events_statements_summary_by_digest` | a7bef5367816ca771571e648ba963515 |
| 2013-11-07 18:24:46 | 0.0084 | 1 | UPDATE `setup_consumers` SET `enabled` = ? WHERE NAME IN (…) | 8205ea424267a604a3a4f68a76bc0bbb |
| 2013-11-07 18:24:46 | 0.0084 | 1 | SHOW GLOBAL STATUS | ddf94d7d7b176021b8586a3cce1e85c9 |
+———————+———+————+——————————————————————————————————————————————————–+———————————-+
This immediately shows me a single simple application query that is executed 60% of the time. Further review of the data and usage pattern shows that should be cached. This is an immediate improvement on system scalability.
While you can look at the raw performance schema data, using ps_helper from Mark Leith makes live easier using the statement_analysis view because of normalizing timers into human readable formats (check out lock_latency).
mysql> select * from ps_helper.statement_analysis order by exec_count desc limit 10;
+——————————————————————-+———–+————+———–+————+—————+————-+————-+————–+———–+—————+————–+————+—————–+————-+——————-+———————————-+
| query | full_scan | exec_count | err_count | warn_count | total_latency | max_latency | avg_latency | lock_latency | rows_sent | rows_sent_avg | rows_scanned | tmp_tables | tmp_disk_tables | rows_sorted | sort_merge_passes | digest |
+——————————————————————-+———–+————+———–+————+—————+————-+————-+————–+———–+—————+————–+————+—————–+————-+——————-+———————————-+
| CREATE VIEW `io_by_thread_by_l … SUM ( `sum_timer_wait` ) DESC | | 146117 | 0 | 0 | 00:01:47.36 | 765.11 ms | 734.74 us | 00:01:02.00 | 3 | 0 | 3 | 0 | 0 | 0 | 0 | c877ec02dce17ea0aca2f256e5b9dc70 |
| SELECT nc . id , nc . name FRO … nc . id WHERE ……._id = ? | | 41394 | 0 | 0 | 16.85 s | 718.37 ms | 407.00 us | 5.22 s | 155639 | 4 | 312077 | 0 | 0 | 0 | 0 | c6e2249eb91767aa09945cbb118adbb3 |
| BEGIN | | 16281 | 0 | 0 | 223.24 ms | 738.82 us | 13.71 us | 0 ps | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 7519b14a899fd514365211a895f5e833 |
| INSERT INTO V…….. VALUES ( … KEY UPDATE v…. = v…. + ? | | 12703 | 0 | 0 | 1.73 s | 34.23 ms | 136.54 us | 696.50 ms | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ffb6231b78efc022175650d37a837b99 |
| SELECT * FROM `D…..` WHERE `name` = ? | | 10620 | 0 | 0 | 3.85 s | 25.21 ms | 362.52 us | 705.16 ms | 1 | 0 | 1 | 0 | 0 | 0 | 0 | d6399273d75e2348d6d7ea872489a30c |
| SELECT COUNT ( * ) FROM T….. … ? LIKE concat ( pattern , ? ) | | 2830 | 0 | 0 | 1.22 s | 2.14 ms | 432.60 us | 215.62 ms | 2830 | 1 | 101880 | 0 | 0 | 0 | 0 | 22d984df583adc9a1ac282239e7629e2 |
| SELECT COUNT ( * ) FROM T….. … KE concat ( ? , pattern , ? ) | | 2727 | 0 | 0 | 932.01 ms | 30.95 ms | 341.77 us | 189.47 ms | 2727 | 1 | 38178 | 0 | 0 | 0 | 0 | a8ee43287bb2ee35e2c144c569a8b2de |
| INSERT IGNORE INTO `K……` ( `id` , `k……` ) VALUES (…) | | 2447 | 0 | 0 | 499.33 ms | 9.65 ms | 204.06 us | 108.28 ms | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 675e32e9eac555f33df240e80305c013 |
| SELECT * FROM `K……` WHERE k…… IN (…) | | 2237 | 0 | 0 | 1.58 s | 62.33 ms | 704.19 us | 345.61 ms | 59212 | 26 | 59212 | 0 | 0 | 0 | 0 | 8aa7dc3b6f729aec61bd8d7dfa5978fa |
| SELECT COUNT ( * ) FROM D….. WHERE NAME = ? OR NAME = ? | | 1285 | 0 | 0 | 797.72 ms | 131.29 ms | 620.79 us | 340.45 ms | 1285 | 1 | 8 | 0 | 0 | 0 | 0 | 1975f53832b0c2506de482898cf1fd37 |
+——————————————————————-+———–+————+———–+————+—————+————-+————-+————–+———–+—————+————–+————+—————–+————-+——————-+———————————-+
Indeed, this simple query highlights a pile of additional information necessary for analysis like:
What is that CREATE VIEW command that’s executed many more times?
In this view, query 2 is executed some 3x more then query 4, yet in my 60 second sample it was 3x less. Has the profile of query load changed. What exactly is being sampled in this view?
The lock_latency shows some incredibility large lock times, over 5 seconds for the top SELECT statement. Is this an outlier. Unfortunately the views give min/avg/max for the total_latency but no breakdown on lock_latency to see how much of a problem this actually is?
A quick note, the statement_analysis_raw view gives you the full SQL statement, so for example the first point listed the statement actually was.
select query from ps_helper.statement_analysis_raw order by exec_count desc limit 1;
CREATE VIEW `io_by_thread_by_latency` AS SELECT IF ( `processlist_id` IS NULL , `SUBSTRING_INDEX` ( NAME , ? , – ? ) , `CONCAT` ( `processlist_user` , ? , `processlist_host` ) ) SYSTEM_USER , SUM ( `count_star` ) `count_star` , `format_time` ( SUM ( `sum_timer_wait` ) ) `total_latency` , `format_time` ( MIN ( `min_timer_wait` ) ) `min_latency` , `format_time` ( AVG ( `avg_timer_wait` ) ) `avg_latency` , `format_time` ( MAX ( `max_timer_wait` ) ) `max_latency` , `thread_id` , `processlist_id` FROM `performance_schema` . `events_waits_summary_by_thread_by_event_name` LEFT JOIN `performance_schema` . `threads` USING ( `thread_id` ) WHERE `event_name` LIKE ? AND `sum_timer_wait` > ? GROUP BY `thread_id` ORDER BY SUM ( `sum_timer_wait` ) DESC
via Planet MySQL
What SQL is running MySQL