application.rb

class ExceptionModel

  def is_false
    false
  end

  def kaboom!
    raise "boom!"
  end

end

class ExceptionBench < Merb::Controller
  ERROR_MSG = "There was a problem"

  def no_exception
    em = ExceptionModel.new
    ERROR_MSG unless em.is_false
  end

  def exception
    em = ExceptionModel.new
    begin
      em.kaboom!
    rescue StandardError => e
      ERROR_MSG
    end
  end

end

class OrmExceptionModel
  include DataMapper::Resource

  property :id,   Serial
  property :name, String, :nullable => false

  def save!
    raise "Save Failed" unless save
  end
end

class OrmExceptionBench < Merb::Controller
  ERROR_MSG = "There was a problem"

  def no_exception
    em = OrmExceptionModel.new
    ERROR_MSG unless em.save
  end

  def exception
    em = ExceptionModel.new
    begin
      em.save!
    rescue StandardError => e
      ERROR_MSG
    end
  end

end

exception.txt

 % ab -n10000 localhost:4000/exception
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking localhost (be patient)
Finished 10000 requests

Server Software:
Server Hostname:        localhost
Server Port:            4000

Document Path:          /exception
Document Length:        19 bytes

Concurrency Level:      1
Time taken for tests:   20.311 seconds
Complete requests:      10000
Failed requests:        0
Write errors:           0
Total transferred:      1540000 bytes
HTML transferred:       190000 bytes
Requests per second:    492.33 [#/sec] (mean)
Time per request:       2.031 [ms] (mean)
Time per request:       2.031 [ms] (mean, across all concurrent requests)
Transfer rate:          74.04 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.0      0       0
Processing:     1    2   3.3      2      57
Waiting:        1    2   3.3      2      57
Total:          1    2   3.3      2      57

Percentage of the requests served within a certain time (ms)
  50%      2
  66%      2
  75%      2
  80%      2
  90%      2
  95%      2
  98%      2
  99%      3
 100%     57 (longest request)

no exception.txt

 % ab -n10000 localhost:4000/no_exception
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking localhost (be patient)
Finished 10000 requests

Server Software:
Server Hostname:        localhost
Server Port:            4000

Document Path:          /no_exception
Document Length:        19 bytes

Concurrency Level:      1
Time taken for tests:   19.541 seconds
Complete requests:      10000
Failed requests:        0
Write errors:           0
Total transferred:      1540000 bytes
HTML transferred:       190000 bytes
Requests per second:    511.73 [#/sec] (mean)
Time per request:       1.954 [ms] (mean)
Time per request:       1.954 [ms] (mean, across all concurrent requests)
Transfer rate:          76.96 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.0      0       0
Processing:     1    2   3.5      2      71
Waiting:        1    2   3.5      2      71
Total:          1    2   3.5      2      71

Percentage of the requests served within a certain time (ms)
  50%      2
  66%      2
  75%      2
  80%      2
  90%      2
  95%      2
  98%      2
  99%      3
 100%     71 (longest request)
  

ORM - exceptions

 % ab -n10000 localhost:4000/orm/exception
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking localhost (be patient)
Completed 1000 requests
Completed 2000 requests
Completed 3000 requests
Completed 4000 requests
Completed 5000 requests
Completed 6000 requests
Completed 7000 requests
Completed 8000 requests
Completed 9000 requests
Completed 10000 requests
Finished 10000 requests


Server Software:        thin
Server Hostname:        localhost
Server Port:            4000

Document Path:          /orm/exception
Document Length:        19 bytes

Concurrency Level:      1
Time taken for tests:   18.786 seconds
Complete requests:      10000
Failed requests:        0
Write errors:           0
Total transferred:      1430000 bytes
HTML transferred:       190000 bytes
Requests per second:    532.31 [#/sec] (mean)
Time per request:       1.879 [ms] (mean)
Time per request:       1.879 [ms] (mean, across all concurrent requests)
Transfer rate:          74.34 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.0      0       4
Processing:     1    2   3.3      2      67
Waiting:        0    2   3.3      2      67
Total:          1    2   3.3      2      67

Percentage of the requests served within a certain time (ms)
  50%      2
  66%      2
  75%      2
  80%      2
  90%      2
  95%      2
  98%      2
  99%      2
 100%     67 (longest request)

ORM - no exception.txt

 % ab -n10000 localhost:4000/orm/no_exception
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking localhost (be patient)
Completed 1000 requests
Completed 2000 requests
Completed 3000 requests
Completed 4000 requests
Completed 5000 requests
Completed 6000 requests
Completed 7000 requests
Completed 8000 requests
Completed 9000 requests
Completed 10000 requests
Finished 10000 requests


Server Software:        thin
Server Hostname:        localhost
Server Port:            4000

Document Path:          /orm/no_exception
Document Length:        19 bytes

Concurrency Level:      1
Time taken for tests:   24.778 seconds
Complete requests:      10000
Failed requests:        0
Write errors:           0
Total transferred:      1430000 bytes
HTML transferred:       190000 bytes
Requests per second:    403.59 [#/sec] (mean)
Time per request:       2.478 [ms] (mean)
Time per request:       2.478 [ms] (mean, across all concurrent requests)
Transfer rate:          56.36 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0    0   0.0      0       4
Processing:     2    2   3.5      2      98
Waiting:        2    2   3.5      2      98
Total:          2    2   3.5      2      98

Percentage of the requests served within a certain time (ms)
  50%      2
  66%      2
  75%      2
  80%      2
  90%      2
  95%      2
  98%      2
  99%      4
 100%     98 (longest request)