Sequel DB Connection PoolTimeout Error

Sequel DB Connection PoolTimeout Error

I have been unable to determine what the cause of the following
Sequel::PoolTimeout error is coming from in a Ruby script I have written:
Sequel::PoolTimeout: Sequel::PoolTimeout
hold at
/Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/connection_pool/threaded.rb:100
hold at
/Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/connection_pool/threaded.rb:93
synchronize at
/Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/database/connecting.rb:234
execute at
/Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/adapters/jdbc.rb:258
execute at
/Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/dataset/actions.rb:793
fetch_rows at
/Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/adapters/jdbc.rb:671
each at
/Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/dataset/actions.rb:143
single_record at
/Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/dataset/actions.rb:583
single_value at
/Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/dataset/actions.rb:591
get at
/Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/dataset/actions.rb:250
empty? at
/Users/username/.rvm/gems/jruby-1.7.4@all/gems/sequel-4.2.0/lib/sequel/dataset/actions.rb:153
scrap at
/Users/username/projectname/processers/get_category.rb:46
each at org/jruby/RubyArray.java:1617
each_with_index at org/jruby/RubyEnumerable.java:920
scrap at
/Users/username/projectname/processers/get_category.rb:44
scrap at
/Users/username/projectname/processers/get_category.rb:32
I have tried this with both MRI and JRuby with exactly the same results.
As per the instructions on the Sequel gem here, I have attempted to raise
the pool_timeout limit as follows:
DB =
Sequel.connect("jdbc:mysql://localhost/project_db?user=USERNAME&password=PASSWD&max_connections=10&pool_timeout=120")
It seems as though the max_connections and pool_timeout may not be
recognized, however I'm not seeing any other way to pass these args on
into the connection.
The actual code that is in question here is: if DB[:products].where(url:
url.to_s).empty?
I have seen the code work just fine for a little bit, but without fail it
fails either right away or after a couple minutes without any
reproducibility in terms of when it occurs. I am starting to suspect that
this is a MySQL config issue or something causing the localhost DBMS to
have some prolonged delays, although, again, I cannot manually reproduce a
visible timeout that I can tell with manual queries, etc.
Any ideas on this issue as to why the timout would keep happening or, more
particularly, how to resolve it either via feeding Sequel proper settings
(perhaps I have a malformed arg list) or modifying MySQL's /etc/my.cnf for
such a scenario?