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Improving documentation for connecting to a replica set

The web pages:
https://docs.mongodb.com/manual/reference/connection-string/
https://docs.mongodb.com/manual/mongo/

Talk about connecting to a replicate set by specifying a list of host:port entries, but they don’t define what it means to connect to a list of host:port entries. Where is that information?

After searching for a while, I found something under:

https://docs.mongodb.com/manual/replication -> Redundancy and Data Availability -> Replication in MongoDB -> Asynchronous Replication -> Automatic Failover -> Read Operations -> Read Preference

which says:

By default, clients read from the primary; however, clients can specify a read preference to send read operations to secondaries

Is there a better place for getting this info?

Seems like this keep piece of information should be included with the connection string info.

Hey @Benjamin_Slade

Do these docs help? Select replica set

High level overview is that the list of servers also the failover to happen if a node goes down. When you connect to a standalone or to one member of a replica set there is no failover.

Thanks, and I appreciate the response, but that doc specifies the connection string format without even a brief reference to what a list of host/port pairs means. So no, it doesn’t help.

My point was that the documentation for the connection string format should include a brief summary of that it means to connect to a list of host/port pairs, and include a link to the “Read Preference” page.

If I was grading this for a class, the “Connection String URI Format” page would get a “D”. Missing key information essential to it’s purpose.

Is it possible to volunteer to update the manual pages? I would be glad to make suggested changes.

Ben

Hi Benjamin,

We definitely appreciate any feedback on improving the documentation.

The bottom right of a documentation page should have a “Was this page helpful” feedback widget. If you click on Yes/No you can provide additional suggestions for improvement:
docs-helpful

Aggregate feedback information on helpfulness of pages is useful to highlight pages needing improvement to the documentation team.

You can also raise suggestions directly in Jira: https://jira.mongodb.org/browse/DOCS.

The Connection String page you referenced does include:

  • a summary under Replica Set Option:

    When connecting to a replica set, provide a seed list of the replica set member(s) to the host[:port] component of the uri.

  • Read Preference Options and links to related pages.

However, “seed list” isn’t currently linked to a longer explanation (which should be added to the Glossary). I raised DOCS-13593 with a suggestion to add this to the glossary:

The seed list of host:port pairs provided in a connection string is used by drivers/clients for initial discovery of the current replica set configuration. Upon successful connection to a member of the seed list, clients will retrieve a canonical list of replica set members to connect to, which may be different from the original seed list. Per the standard Server Discovery and Monitoring (SDAM) specification, clients will use the hostnames listed in the replica set config, not the seed list.

Regards,
Stennie

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