MongoDB write durability via Ruby Wrapper

Question

Why does Mongo sometimes write and sometimes doesn't? The code can probably give a better idea of what I am talking about:

Note:

• pmap is a multi-threaded map.
• db version v2.0.2, pdfile version 4.5

dbMongo = Mongo::Connection.new.db("test") #Mongo Database.
coll = dbMongo.collection("test-collection")
glob = Array.new

#///////Generates hashes////
(1...100).to_a.pmap(10) do |x|
  b_test = stack_hash(x) #generates an array of hashes
  glob << b_test
end

#///////Tests/////
glob = glob.flatten.uniq.compact 
p glob.length #=> 3027


p coll.drop #=> true
coll.insert(glob)
p coll.count.to_s + " <batch insert" #=> "2550 <batch insert"

p coll.drop #=> true
glob.each do |x|
  coll.insert(x)
end
p coll.count.to_s + " <single thread insert" #=> "3000 <single thread insert"


p coll.drop #=> true
glob.each do |x|
  sleep(0.1)
  coll.insert(x)
end
p coll.count.to_s + " <single thread slow insert" #=> "3000 <single thread slow insert"

Answer 1

what's the error you're seeing? Can you try setting the driver's write to "safe", so you'll know whether Mongo returned an error or not?

coll.insert(x, :safe => true)