asynchronous发送邮件时，“SSL_read：证书已在哈希表中”
使用ActionMailerasynchronous发送延迟的电子邮件时，我一直在使用SSL_read: cert already in hash table的消息得到一个OpenSSL::SSL::SSLError消息。
我们使用Sidekiq将所有电子邮件asynchronous发送出去。 当在Sidekiq GitHub仓库中提出这个问题时，我被告知Sidekiq不知道或pipe理SSL连接。
我们的应用程序在OpenSSL 0.9.8k 25 Mar 2009运行OpenSSL 0.9.8k 25 Mar 2009 Heroku上运行。
我们在其他工作中多次看到这个错误，并且发现有时工作得到处理，但是有时候却没有。
这是一个OpenSSL线程问题，其中多个Sidekiq线程正在尝试使用相同的SSL连接？ 有一个解决这个问题吗？
这是我们得到的堆栈跟踪：
[PROJECT_ROOT]/vendor/ruby-2.0.0/lib/ruby/2.0.0/openssl/buffering.rb:175:in `sysread_nonblock` [PROJECT_ROOT]/vendor/ruby-2.0.0/lib/ruby/2.0.0/openssl/buffering.rb:175:in `read_nonblock` [PROJECT_ROOT]/vendor/ruby-2.0.0/lib/ruby/2.0.0/net/protocol.rb:153:in `rbuf_fill` [PROJECT_ROOT]/vendor/ruby-2.0.0/lib/ruby/2.0.0/net/protocol.rb:134:in `readuntil` [PROJECT_ROOT]/vendor/ruby-2.0.0/lib/ruby/2.0.0/net/protocol.rb:144:in `readline` [PROJECT_ROOT]/vendor/ruby-2.0.0/lib/ruby/2.0.0/net/smtp.rb:932:in `recv_response` [PROJECT_ROOT]/vendor/ruby-2.0.0/lib/ruby/2.0.0/net/smtp.rb:903:in `block in data` [PROJECT_ROOT]/vendor/ruby-2.0.0/lib/ruby/2.0.0/net/smtp.rb:942:in `critical` [PROJECT_ROOT]/vendor/ruby-2.0.0/lib/ruby/2.0.0/net/smtp.rb:896:in `data` [PROJECT_ROOT]/vendor/ruby-2.0.0/lib/ruby/2.0.0/net/smtp.rb:663:in `block in send_message` [PROJECT_ROOT]/vendor/ruby-2.0.0/lib/ruby/2.0.0/net/smtp.rb:852:in `rcptto_list` [PROJECT_ROOT]/vendor/ruby-2.0.0/lib/ruby/2.0.0/net/smtp.rb:663:in `send_message` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/mail-2.5.4/lib/mail/network/delivery_methods/smtp.rb:113:in `block in deliver!` [PROJECT_ROOT]/vendor/ruby-2.0.0/lib/ruby/2.0.0/net/smtp.rb:521:in `start` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/mail-2.5.4/lib/mail/network/delivery_methods/smtp.rb:112:in `deliver!` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/mail-2.5.4/lib/mail/message.rb:2129:in `do_delivery` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/mail-2.5.4/lib/mail/message.rb:232:in `block in deliver` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/actionmailer-4.0.3/lib/action_mailer/base.rb:456:in `block in deliver_mail` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.3/lib/active_support/notifications.rb:159:in `block in instrument` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.3/lib/active_support/notifications/instrumenter.rb:20:in `instrument` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.3/lib/active_support/notifications.rb:159:in `instrument` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/actionmailer-4.0.3/lib/action_mailer/base.rb:454:in `deliver_mail` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/mail-2.5.4/lib/mail/message.rb:232:in `deliver` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/extensions/action_mailer.rb:20:in `perform` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/processor.rb:49:in `block (3 levels) in process` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/middleware/chain.rb:122:in `call` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/middleware/chain.rb:122:in `block in invoke` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/newrelic_rpm-3.7.1.182/lib/new_relic/agent/instrumentation/sidekiq.rb:30:in `block in call` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/newrelic_rpm-3.7.1.182/lib/new_relic/agent/instrumentation/controller_instrumentation.rb:339:in `perform_action_with_newrelic_trace` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/newrelic_rpm-3.7.1.182/lib/new_relic/agent/instrumentation/sidekiq.rb:21:in `call` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/middleware/chain.rb:124:in `block in invoke` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-failures-0.3.0/lib/sidekiq/failures/middleware.rb:10:in `call` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/middleware/chain.rb:124:in `block in invoke` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-unique-jobs-2.7.0/lib/sidekiq-unique-jobs/middleware/server/unique_jobs.rb:15:in `call` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/middleware/chain.rb:124:in `block in invoke` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/middleware/server/active_record.rb:6:in `call` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/middleware/chain.rb:124:in `block in invoke` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/middleware/server/retry_jobs.rb:62:in `call` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/middleware/chain.rb:124:in `block in invoke` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/middleware/server/logging.rb:11:in `block in call` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/logging.rb:22:in `with_context` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/middleware/server/logging.rb:7:in `call` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/middleware/chain.rb:124:in `block in invoke` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/middleware/chain.rb:127:in `call` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/middleware/chain.rb:127:in `invoke` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/processor.rb:48:in `block (2 levels) in process` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/processor.rb:105:in `stats` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/processor.rb:47:in `block in process` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/processor.rb:86:in `do_defer` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/sidekiq-2.17.2/lib/sidekiq/processor.rb:37:in `process` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/celluloid-0.15.2/lib/celluloid/calls.rb:25:in `public_send` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/celluloid-0.15.2/lib/celluloid/calls.rb:25:in `dispatch` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/celluloid-0.15.2/lib/celluloid/calls.rb:122:in `dispatch` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/celluloid-0.15.2/lib/celluloid/actor.rb:322:in `block in handle_message` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/celluloid-0.15.2/lib/celluloid/actor.rb:416:in `block in task` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/celluloid-0.15.2/lib/celluloid/tasks.rb:55:in `block in initialize` [PROJECT_ROOT]/vendor/bundle/ruby/2.0.0/gems/celluloid-0.15.2/lib/celluloid/tasks/task_fiber.rb:13:in `block in create
当中间CA证书与电子邮件服务器证书一起提供时，可能会发生这种情况，但也已经存在于本地证书存储区中。 这个版本的OpenSSL或者电子邮件库如何处理OpenSSL错误（这不应该是致命的）可能是一个错误。
