ThreadsafeBenchmark

When testing products such as services which need to be stress-tested prior to release, it’s necessary to use multi-threading to get as close to real world usage as possible. This gem, though not intended to be a replacement for full-fledged testing suites such as LoadRunner, can provide instantaneous results to facilitate TDD programming. To reduce the duplication of code, the gem utilizes Ruby’s built-in Benchmark module for the base functionality while preventing the output from clobbering through the use of thread-specific IO buffers.

require 'threadsafe_benchmark'
include ThreadsafeBenchmark

threads = []
max_num = 5000

5.to_i.times { |i|
threads << Thread.new(max_num) { |n|
threadsafe_bm(6) { |x|
x.report("for:") { for i in 1..n; a = "1"; end }
x.report("times:") { n.times do ; a = "1"; end }
x.report("upto:") { 1.upto(n) do ; a = "1"; end }
}
}
}

threads.each { |t| t.join }

Using the standard Benchmark, the results would be printed haphazardly making it difficult to read and interpret. But ThreadsafeBenchmark cleans everything up giving us nicely laid out columns.

user system total real
for 0.000000 .000000 .000000 ( 0.002889)
times 0.000000 .000000 .000000 ( 0.002477)
upto 0.000000 .000000 .000000 ( 0.002479)
for 0.000000 .000000 .000000 ( 0.002401)
times 0.010000 .000000 .010000 ( 0.002586)
upto 0.000000 .000000 .000000 ( 0.002413)
for 0.000000 .000000 .000000 ( 0.002205)
times 0.010000 .000000 .010000 ( 0.002245)
upto 0.000000 .000000 .000000 ( 0.002272)
for 0.000000 .000000 .000000 ( 0.001822)
times 0.010000 .000000 .010000 ( 0.001958)
upto 0.000000 .000000 .000000 ( 0.001943)
for 0.010000 .000000 .010000 ( 0.010090)
times 0.010000 .000000 .010000 ( 0.009225)
upto 0.010000 .000000 .010000 ( 0.007986)

The gem and source files are available at Rubyforge.

ThreadsafeBenchmark

When testing products such as services which need to be stress-tested prior to release, it’s necessary to use multi-threading to get as close to real world usage as possible. This gem, though not intended to be a replacement for full-fledged testing suites such as LoadRunner, can provide instantaneous results to facilitate TDD programming. To reduce the duplication of code, the gem utilizes Ruby’s built-in Benchmark module for the base functionality while preventing the output from clobbering through the use of thread-specific IO buffers.

require 'threadsafe_benchmark'
include ThreadsafeBenchmark

threads = []
max_num = 5000

5.to_i.times { |i|
threads << Thread.new(max_num) { |n|
threadsafe_bm(6) { |x|
x.report("for:") { for i in 1..n; a = "1"; end }
x.report("times:") { n.times do ; a = "1"; end }
x.report("upto:") { 1.upto(n) do ; a = "1"; end }
}
}
}

threads.each
Continue reading "ThreadsafeBenchmark"

Enhanced Migrations v1.2.0

The original release of this highly useful plugin marked a turning point in collaborative Rails development by freeing the developer to commit their database migration without fear of having it ignored because of a higher placed migration number. This latest release includes some minor bug fixes plus a useful method for stepping through migrations one at a time without the need for copying and pasting long version numbers.

  1. Fixed bug where an empty migrations_info table would create a non-parseable schema.rb.
  2. Made plugin database independent.
  3. Added capability to step through migrations using VERSION=[previous, next, first and last].
  4. dump_schema_information now returns all migrations, not just latest (credit to Fran├žois Beausolei).
  5. Added tests which use SQLite and a task (enhanced_migrations:clean_sqlite_db) to help with testing.

As an example of item number three, consider the following situation. Using the enhanced migrations plugin, you’ve just created a migration that adds a new table to your database. Upon running it, you discover that you used the wrong data type for a column. Rather than having to copy and paste the previous migration’s version number, simply using ‘previous’ in the VERSION number will now suffice.


rake db:migrate VERSION=previous

This also works using prev along with next, first and last for their respective operations. Keep in mind that first will go to the first migration and is not the same as VERSION=0.

Migrate as usual


shell> rake db:migrate
== CreateRecipesTable: migrating ==============================================
-- create_table(:recipes)
-> 0.0902s
== CreateRecipesTable: migrated (0.0904s) =====================================

== AddRecipesForUser1: migrating ==============================================
-- execute("INSERT INTO recipes (name, owner) VALUES ('Lemon Meringue Pie', 'user1')")
-> 0.3684s
== AddRecipesForUser1: migrated (0.5302s) =====================================

== AddRecipesForUser2: migrating ==============================================
-- execute("INSERT INTO recipes (name, owner) VALUES ('Steak and Kidney Pie', 'user2')")
-> 0.2574s
== AddRecipesForUser2: migrated (0.3962s) =====================================

Migrate to the previous version


shell> rake db:migrate VERSION=previous
== AddRecipesForUser2: reverting ==============================================
-- execute("DELETE FROM recipes WHERE owner = 'user2'")
-> 0.4512s
== AddRecipesForUser2: reverted (0.4516s) =====================================

Migrate to the first version


shell> rake db:migrate VERSION=first
== AddRecipesForUser1: reverting ==============================================
-- execute("DELETE FROM recipes WHERE owner = 'user1'")
-> 0.1676s
== AddRecipesForUser1: reverted (0.1678s) =====================================

Migrate another previous version, essentially the same as VERSION=0 since we are already at the first migration.


shell> rake db:migrate VERSION=previous
== CreateRecipesTable: reverting ==============================================
-- drop_table(:recipes)
-> 0.1680s
== CreateRecipesTable: reverted (0.1683s) =====================================

How to get
Download the gem from Rubyforge and install it like so:

sudo gem install enhanced_migrations-1.2.1.gem

Update – 11/15/2007
The previous version had a small bug that was discovered during use here that sometimes caused an app’s database yaml file to be overwritten by the gem’s database config which is used only for testing. The chances of this happening outside of our particular setup are small but we felt it warranted an immediate fix. We’ve also added a gzip’d source file for the plugin fans out there.

Links in the post have been updated to reflect the location of this new release.

Enhanced Migrations v1.2.0

The original release of this highly useful plugin marked a turning point in collaborative Rails development by freeing the developer to commit their database migration without fear of having it ignored because of a higher placed migration number. This latest release includes some minor bug fixes plus a useful method for stepping through migrations one at a time without the need for copying and pasting long version numbers.

  1. Fixed bug where an empty migrations_info table would create a non-parseable schema.rb.
  2. Made plugin database independent.
  3. Added capability to step through migrations using VERSION=[previous, next, first and last].
  4. dump_schema_information now returns all migrations, not just latest (credit to Fran├žois Beausolei).
  5. Added tests which use SQLite and a task (enhanced_migrations:clean_sqlite_db) to help with testing.

As an example of item number three, consider the following situation. Using the enhanced migrations plugin, you’ve just created a migration that adds a new table to

Continue reading “Enhanced Migrations v1.2.0”