WHAT

We noticed that setting timeout_ms=0 (for transactions) or default_timeout_ms=0 (for sessions) results in the transaction being aborted immediately due to a timeout error. This is inconsistent to how other operations behave when timeout_ms is set to 0 where the documentation usually states something like

The operation timeout in milliseconds. Must be a non-negative integer. An explicit value of 0 means infinite. The default value is unset which means the value is inherited from the collection or the database or the client.

We believe this to be the case because 0 is treated like any other value when determining the transaction deadline whereas CsotTimeoutHolder#timeout? treats them differently

REFERENCES

• https://github.com/mongodb/mongo-ruby-driver/blob/master/lib/mongo/session.rb#L448
• https://www.rubydoc.info/github/mongodb/mongo-ruby-driver/Mongo/Collection/View 
• https://github.com/mongodb/mongo-ruby-driver/blob/master/lib/mongo/csot_timeout_holder.rb#L37