How to handle Mogo replica set Mongo::ConnectionFailure exception in Ruby ?
Tried:
begin
$mongo = Mongo::MongoReplicaSetClient.new(['seed1:27017', 'seed2:27017', 'seed3:27017'], :read => :primary, :rs_name => 'rs0', :connect_timeout => 30, :op_timeout => 30)
mongo = $mongo.db('db_name')
rescue Exception => ex
puts ex.message
rescue Mongo::ConnectionFailure => ex
puts ex.message
rescue RuntimeError => ex
puts ex.message
rescue => ex
puts ex.message
end
No one can handle exception message of rescue block
solved with:
def rescue_mongo_failures(max_retries=60)
retries = 0
begin
yield
rescue Mongo::ConnectionFailure => ex
retries += 1
# here you can get ex.message
raise ex if retries > max_retries
retry
end
end
def rescue_mongo_failures do
$mongo = Mongo::MongoReplicaSetClient.new(['seed1:27017', 'seed2:27017', 'seed3:27017'], :read => :primary, :rs_name => 'rs0', :connect_timeout => 30, :op_timeout => 30)
mongo = $mongo.db('db_name')
$mongo.db.stats
end
Related
Open-uri and nokogiri are slow to scrape the site I want hence the Net::OpenTimeout execution expired error. I attempted to code a custom error with rescue however I do not know what condition I can look for to raise that custom error.
I attempted to few if else statements however I really just guessed how to check if I was gonna get that error. I hard coded a condition that failed and thus rescued the error. I am very new to ruby and custom errors. In fact this is my first.
class Scrape
Base = 'http://www.wine.com'
##menu = []
##pages = []
def self.index
index_url = Base + "/list/wine/7155?sortBy=savings&pricemax=90"
#below is where I need to check for the condition to
raise the error
if doc = Nokogiri::HTML(open(index_url))
container = doc.css('.prodList')
wines = container.css('.prodItem')
wines.each do |wine|
##menu << {
:link => wine.css('.prodItemInfo_link').attribute('href').value,
:name => wine.css('.prodItemInfo_name').text,
:rating => (wine.css('.averageRating_average').text.to_i) > 0 ?
(wine.css('.averageRating_average').text) : 'no rating',
:price => wine.css('.productPrice_price-saleWhole').text.strip
}
end
##menu.each do |item|
Bottle.new.create(item)
end
else
begin
raise Custom_error
rescue Custom_error => error
puts error.message
end
end
end
def self.scrape_page(wine_obj)
wine_link = wine_obj.link
individual_page = Base + wine_link
docu = Nokogiri::HTML(open(individual_page))
y = docu.css('.viewMoreModule_text')
more = docu.css('.viewMoreModule_text')
##pages << {
:obj => wine_obj,
:name => docu.css('.pipName').text,
:alcohol_percent => y
x = docu.css('.mobileProdAttrs').css('.prodAlcoholPercent')
y = x.css('.prodAlcoholPercent_percent').text,
:price => docu.css('span.productPrice_price-saleWhole').text,
:origin => docu.css('span.prodItemInfo_originText a').text,
:winemaker_notes => docu.css('.viewMoreModule_text').first.text,
:more => y[2].text,
:rating => docu.css('span.averageRating_average').first.text
}
Page.create_find_by_name( ##pages.last )
end
def self.pages
##pages
end
end
class Cli
def run
puts 'loading from cyberspace'
Scrape.index
Bottle.make_list
controller
end
def controller
input = ''
response = ''
puts ' '
view
while input != 11
response = gets.chomp.to_i
input = "#{response}11".to_i
if input == 111
menu
elsif input == 11
exit
elsif input > 0 && input < 26
find_by_input(input)
elsif input != 0 && input != 111
error_1
end
end
end
def view
puts "welcome to the wine bar"
puts "================="
puts " W I N E "
puts " B A R "
puts "================="
puts " "
puts "type 1 for list of wine"
puts " "
puts "type 0 to exit "
end
def menu
wines = Bottle.list
second_input = ''
while second_input != 0
puts "<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>"
puts "type the corresponding number to view more wine info"
puts
"__________________________________________________________________"
wines.each do |wine|
puts "#{wine.index}) #{wine.name} #{wine.price}"
end
second_input = gets.chomp.to_i
if second_input > 0 && second_input < 26
find_by_input(second_input)
elsif second_input == 0
exit
second_input = 0
elsif second_input > 25 && second_input != 101
error_1
end
end
puts <<-DOC
the the wine number again
for winemaker notes
DOC
end
def find_by_input(input)
while input != 0
selection = Bottle.find_by_input(input)
puts "NAME: #{selection.name}"
puts "PRICE: $#{selection.price}"
puts "RATING: #{selection.rating}"
puts "________________________________________"
puts " type #{input} again "
puts " for more info "
puts " provided by the winemaker "
# reseting input and extending user control functionality
third_input = ''
third_input = gets.chomp.to_i
if third_input == selection.index
response = Scrape.scrape_page(selection)
view_2(response, third_input)
elsif input == 0
exit
end
end
end
def view_2(response, old_input)
next_input = ''
while next_input != 0
puts "Alcohol Percent: #{response.alcohol_percent}"
puts "Winemaker Notes: #{response.winemaker_notes}"
puts " "
puts "Type #{old_input} again for more!!"
next_input = gets.chomp.to_i
if next_input == old_input
input = 0
next_input = 0
# refacort as it puts out 88 again and should not. Also 0 is not
exiting with correct behavior
# refactor so looking for "#{input}"1 to prevent the recall of
input
more(response)
end
end
end
def more(response)
puts response.more
puts menu
end
def error_1
puts " WHOA coder "
puts "type a better number!"
end
def exit
puts <<-DOC
well that was fun
Thank you for checking out
my first cli program
DOC
end
end ```
```class Page
attr_accessor :alcohol_percent, :price, :name, :origin, :winemaker_notes,
:rating, :more, :obj
##web_pages = []
def self.create_find_by_name(hash)
if answer = ##web_pages.find{ |obj| obj.name == hash[:name]}
answer
else
self.new.create(hash)
end
end
def create(hash)
hash.each do |key, value|
self.send(("#{key}="), value)
end
save
view_more
end
def view_more
##web_pages.last
end
def save
##web_pages << self
end
end
attr_accessor :link, :name, :price, :rating, :index
##bottles = []
def create(hash)
hash.each do |key, words|
self.send(("#{key}="), words )
end
save
end
def save
##bottles << self
end
def self.make_list
##numbered_list = ##bottles.sort{ |x,y| x.price <=>
y.price}.map.with_index(1) do
|w,i| w.index = i
w
end
end
def self.list
##numbered_list
end
def self.find_by_input(input)
a = ##numbered_list.find{ |wine| wine.index == input}
# puts "#{a.name} $#{a.price} rating: #{a.rating}"
# puts "type #{input} again for winemaker notes"
# more = ''
# while more != 0
# more = gets.chomp.to_i
# (input == more) ? (Scrape.scrape_page(a.link)) : (self.list)
# end
end
end
class Scrape
Base = 'http://www.wine.com'
##menu = []
##pages = []
def self.index
index_url = Base + "/list/wine/7155?sortBy=savings&pricemax=90"
if doc = Nokogiri::HTML(open(index_url))
container = doc.css('.prodList')
wines = container.css('.prodItem')
wines.each do |wine|
##menu << {
:link => wine.css('.prodItemInfo_link').attribute('href').value,
:name => wine.css('.prodItemInfo_name').text,
:rating => (wine.css('.averageRating_average').text.to_i) > 0 ?
(wine.css('.averageRating_average').text) : 'no rating',
:price => wine.css('.productPrice_price-saleWhole').text.strip
}
end
##menu.each do |item|
Bottle.new.create(item)
end
else
begin
raise Custom_error
rescue Custom_error => error
puts error.message
end
end
end
def self.scrape_page(wine_obj)
wine_link = wine_obj.link
individual_page = Base + wine_link
docu = Nokogiri::HTML(open(individual_page))
y = docu.css('.viewMoreModule_text')
more = docu.css('.viewMoreModule_text')
##pages << {
:obj => wine_obj,
:name => docu.css('.pipName').text,
alcholo = docu.css('.mobileProdAttrs').css('.prodAlcoholPercent'),
:alcohol_percent => alcholo.css('.prodAlcoholPercent_percent').text,
:price => docu.css('span.productPrice_price-saleWhole').text,
:origin => docu.css('span.prodItemInfo_originText a').text,
:winemaker_notes => docu.css('.viewMoreModule_text').first.text,
:more => y[2].text,
:rating => docu.css('span.averageRating_average').first.text
}
Page.create_find_by_name( ##pages.last )
end
def self.pages
##pages
end
end
When the internet connection is down/too slow the custom error is raised.
When an exception is thrown, the program stops its normal flow. You need to surround the part of the code that can throw an exception with a begin..rescue clause, and attempt to handle it, re-raise it, or raise another exception instead.
In your example, that would be:
begin
Nokogiri::HTML(open(url))
rescue Net::OpenTimeoutError => e
# log the error message if needed, raise your CustomError instead
raise CustomError, e.message
end
You can omit the begin, and put a rescue clause at the end of the method, ruby will interpret this as if the entire method body was wrapped in a begin..rescue block, something like this:
def open_page(url)
return Nokogiri::HTML(open(url))
rescue Net::OpenTimeoutError => e
raise CustomError, e.message
end
I would want to check if there is a connection with the database before execute the query .
But when I write if mysql_connection ... then it passes twice on mysql_connection:
def mysql_connection
puts "mysql_connection 1"
read_config_file
#connexion = Mysql2::Client.new(:host => #conf['host'], :username => #conf['user'], :password => #conf['password'], :database=> #conf['base'], :port => #conf['port'])
end
# USER QUERY MYSQL
def mysql_select_user(value)
puts "select"
# if mysql_connection then
p = mysql_connection.query("select #{value} from User")
p.each do |f|
puts "value : #{f}"
mysql_close
end
# else
# end
end
Use Mysql2::Client#ping method (from docs: http://www.rubydoc.info/gems/mysql2/0.3.13/Mysql2/Client#ping-instance_method)
I have a program that uses a method for verification, if that verification failed I would like to return to the method it was called from, for example:
def obtain_pokemon_name
print 'Enter Pokemon: '
pokemon = gets.chomp.capitalize
obtain_basic_attack(pokemon)
end
def obtain_basic_attack(poke)
print 'Enter basic attack: '
basic_attack = gets.chomp.downcase
check_attacks(poke, basic_attack)
obtain_spec_attack(poke)
end
def obtain_spec_attack(poke)
print 'Enter special attack: '
spec_attack = gets.chomp.downcase
check_attacks(poke, spec_attack)
end
def check_attacks(pokemon, attack)
if POKEMON_ATTACKS[pokemon][attack] == nil
puts "#{attack} is not one of #{pokemon}'s attacks, try again.."
return # to where this function was called
else
attack
end
end
begin
obtain_pokemon_name
rescue => e
puts "Failed with error code: #{e}"
end
When this is run:
Enter Pokemon: arbok
Enter basic attack: eat
eat is not one of Arbok's attacks, try again..
Enter special attack: test
test is not one of Arbok's attacks, try again..
Attack list:
POKEMON_ATTACKS = {
'Bulbasaur' => {'tackle' => 10.9, 'vine whip' => 15.4, 'power whip' => 21.4, 'seed bomb' => 12.5, 'sludge bomb' => 19.2},
'Ivysaur' => {'razor leaf' => 10.3, 'vine whip' => 15.4, 'power whip' => 21.4, 'sludge bomb' => 19.2, 'solar beam' => 13.3},
'Kakuna' => {'bug bite' => 13.3, 'poison sting' => 10.3, 'struggle' => 8.8},
'Beedrill' => {'bug bite' => 13.3, 'poison jab' => 14.3, 'aerial ace' => 8.6, 'sludge bomb' => 19.2, 'x-scissor' => 14.3},
'Pidgey' => {'quick attack' => 7.5, 'tackle' => 10.9, 'aerial ace' => 8.6, 'air cutter' => 7.6, 'twister' => 5.6},
'Ekans' => {'acid' => 9.5, 'poison sting' => 10.3, 'gunk shot' => 20.0, 'sludge bomb' => 19.2, 'wrap' => 3.8},
'Arbok' => {'acid' => 9.5, 'bite' => 12.0, 'dark pulse' => 12.9, 'gunk shot' => 20.0, 'sludge wave' => 17.6},
}
So my question is, if the attack is not present in the data, how can I return back to the calling method? So for instance if I call arbok and his attack is tackle if it doesn't exist in the hash, how would I return to the obtain_basic_attack(poke) method?
RIght here:
puts "#{attack} is not one of #{pokemon}'s attacks, try again.."
return # to where this function was called
you should call the original method again. i.e.
if POKEMON_ATTACKS[pokemon][attack] == nil
puts "#{attack} is not one of #{pokemon}'s attacks, try again.."
return obtain_spec_attack(poke)
You could alternatively add this logic to obtain_spec_attack:
def obtain_spec_attack(poke)
loop do
print 'Enter special attack: '
spec_attack = gets.chomp.downcase
attack_found = check_attacks(poke, spec_attack)
if attack_found
break attack_found # this will return attack_found from the loop
else
puts "attack not found"
end
end
end
edit
looking at your question again, I realize you want to return to a method multiple levels up. You could use the approaches I've already outlined, or alternatively use rescue:
def obtain_basic_attack(poke)
begin
print 'Enter basic attack: '
basic_attack = gets.chomp.downcase
check_attacks(poke, basic_attack)
obtain_spec_attack(poke)
rescue AttackNotFoundError
retry # runs the 'begin' block again
end
end
def obtain_spec_attack(poke)
print 'Enter special attack: '
spec_attack = gets.chomp.downcase
check_attacks(poke, spec_attack)
end
def check_attacks(pokemon, attack)
if POKEMON_ATTACKS[pokemon][attack] == nil
puts "#{attack} is not one of #{pokemon}'s attacks, try again.."
raise AttackNotFoundError
else
attack
end
end
In order to use a custom error like AttackNotFoundError, you need to define the error class somewhere:
class AttackNotFoundError < StandardError; end
You could use any error really, such as raise StandardError, but it's better to restrict what errors you're rescuing so that you don't accidentally rescue an unrelated error.
My initialization failed randomly.
What the better way to implement the init ?
#client = Mongo::Client.new([ cfg["HOST"] ], :database => cfg["NAME"])
At least retry 10 times.
I found some solution like that
begin
coll.insert( { "counter" => i, "named" => "name#{i}" })
rescue Mongo::ConnectionFailure => ex
sleep(0.5)
coll.insert( { "counter" => i, "named" => "name#{i}" })
end
Is there any elegant way to do so ? because I need to do similar init in my project many places
You could extract your connection logic to another method and do
connections = 0
while connections < 10 # or however many
begin
try_connecting
break # only called when no error raised
rescue Mongo::ConnectionFailure => ex
connections += 1
sleep(0.5)
end
end
or maybe this:
def connect
try_connecting
rescue Mongo::ConnectionFailure => ex
fail = true
sleep(0.5)
ensure
return defined?(fail)
end
10.times { break unless connect }
I have a working TCP/IP socket server that loads 3-flash files in succession. How can I unload previous files and eliminate the garbage build up?
2-Flash clients are active, 1-the loader, 2-the next Flash file being loaded, however "the Flash files don't unload." Maybe there's a "put - kill" method or something similar to addChild removeChild in as3. Any resource would help, since I'm not very familiar with Ruby.
Files involved
POLICY SERVER "server lets Flash files play"
policyserver_little.rb
RUBY TCP/IP SOCKET SERVER "server plays loader, that loads 3-Flash files"
server_little#.rb
FLASH LOADER "client"
loader_little.swf
FLASH MOVIES "numbers_odom.swf, numbers_fruits.swf, $mil.swf"
"msg1, msg2, msg3"
WHAT I SEE
def worker==>end
There's no method to unload.
RUBY SERVER server_little#.rb
require 'socket'
require 'rexml/document'
include Socket::Constants
def create_xml_msg(msg, parent)
el = nil
msg.each do |key, value|
if parent
el = parent.add_element(key)
else
el = REXML::Element.new(key)
end
if value.instance_of?(Hash)
create_xml_msg(value, el)
else
el.text = value.to_s
end
end
return el
end
def worker(client, client_sockaddr, worker_number)
$tid << Thread.new([client, client_sockaddr, worker_number]) do |cl|
Thread.current[:number] = cl[2]
puts("\nThread #{cl[2]} servicing #{Socket.unpack_sockaddr_in(cl[1]).join(':')}")
#2
seq_no = cl[2] * 10000000
loop do
begin
msg1 = {"msg" => {"head" => {"type" => "frctl", "seq_no" => seq_no, "version" => 1.0},
"body" => {"file" => "numbers_odom.swf", "start" => 5,
"end" => 3000, "rate" => 40, "duration" => 60}}}
msg2 = {"msg" => {"head" => {"type" => "frctl", "seq_no" => seq_no, "version" => 1.0},
"body" => {"file" => "numbers_fruits.swf", "start" => 5, "end" => 3000, "rate" => 40, "duration" => 60}}}
msg3 = {"msg" => {"head" => {"type" => "frctl", "seq_no" => seq_no, "version" => 1.0},
"body" => {"file" => "$mil.swf", "start" => 5,
"end" => 3000, "rate" => 40, "duration" => 60}}}
[ msg1, msg2, msg3 ].each do |m|
seq_no += 1
m["msg"]["head"]["seq_no"] = seq_no
xml_msg = create_xml_msg(m, nil)
xml_msg.write(cl[0], 0)
cl[0].putc 0
sleep 10
end
rescue
cl[0].close
puts "\nThread #{Thread.current[:number]} exiting..."
Thread.exit
end
end
end
end
$tid = [] # array of active worker thread ids
$wno = [] # array of active worker numbers
$worker_count = 0
$max_workers = 3
$wlist = Array(1..$max_workers) #array of all possible worker numbers
socket = Socket.new( AF_INET, SOCK_STREAM, 0 )
sockaddr = Socket.pack_sockaddr_in( 1999, '0.0.0.0' )
begin
socket.bind( sockaddr )
socket.listen( 5 )
rescue
print $!.class, " ", $!
sleep 3
retry
end
loop do
begin
$tid.each do |t|
if (t.status == false || t.status == "aborting" )
t.join
$wno.delete(t[:number])
$tid.delete(t)
$worker_count -= 1
puts("\nWorker count #{$worker_count}")
end
end
client, client_sockaddr = socket.accept_nonblock
if (client)
if ($worker_count >= $max_workers)
puts "\n too many clients...\n"
client.puts("<msg>error: too many clients; closing connection...</msg>")
client.close
else
$worker_count += 1
$wlist.each do |w| #find a hole in worker number list
if (!$wno.include?(w))
$wno << w #add new worker number to the active worker num array
worker(client, client_sockaddr, w)
break
end
end
puts("\nWorker count #{$worker_count}")
end
end
rescue Errno::EAGAIN, Errno::ECONNABORTED, Errno::EINTR, Errno::EWOULDBLOCK
IO.select([socket], nil, nil, 1)
retry
end
end
REFERENCE
Ruby version 186-25
http://rubylearning.com/satishtalim/ruby_threads.html
A very good resource for socket programming in ruby:
Ruby Sockets: IBM
It was tough for me to get a feel for your code by reading through it, so I can't give you a direct answer. However I can tell you that if you want a good resource for sockets in ruby that pdf is it.
In general i think the only way to eliminate garbage is to fork off a process, let it do the garbage-y stuff then die. If that's your question. NB that jruby, macruby, and rubinius have more advanced GC's.
-r