Module: Mongo::ServerSelector

Relationships & Source Files
Namespace Children
Classes: `Base`, `Nearest`, `Primary`, `PrimaryPreferred`, `Secondary`, `SecondaryPreferred`
Defined in:	lib/mongo/server_selector.rb, lib/mongo/server_selector/base.rb, lib/mongo/server_selector/nearest.rb, lib/mongo/server_selector/primary.rb, lib/mongo/server_selector/primary_preferred.rb, lib/mongo/server_selector/secondary.rb, lib/mongo/server_selector/secondary_preferred.rb

Overview

Functionality for getting an object able to select a server, given a preference.

Since:

2.0.0

Constant Summary

LOCAL_THRESHOLD =

The max latency in seconds between the closest server and other servers considered for selection.
Since:
- 2.0.0
# File 'lib/mongo/server_selector.rb', line 35
```
0.015
```

PREFERENCES =

Hash lookup for the selector classes based off the symbols provided in configuration.

Since:

2.0.0

# File 'lib/mongo/server_selector.rb', line 56

{
  nearest: Nearest,
  primary: Primary,
  primary_preferred: PrimaryPreferred,
  secondary: Secondary,
  secondary_preferred: SecondaryPreferred
}.freeze

PRIMARY =

ServerSelector::Primary read preference.
Since:
- 2.1.0
# File 'lib/mongo/server_selector.rb', line 50
```
Options::Redacted.new(mode: :primary).freeze
```
SERVER_SELECTION_TIMEOUT =

How long to block for server selection before throwing an exception.
Since:
- 2.0.0
# File 'lib/mongo/server_selector.rb', line 40
```
30
```
SMALLEST_MAX_STALENESS_SECONDS =

The smallest allowed max staleness value, in seconds.
Since:
- 2.4.0
# File 'lib/mongo/server_selector.rb', line 45
```
90
```

Instance Method Summary

#get(preference = {})

Create a server selector object.
#primary Internal use only

Returns the primary server selector.

Instance Method Details

#get(preference = {})

Create a server selector object.

Examples:

Get a server selector object for selecting a secondary with

specific tag sets.
Mongo::ServerSelector.get(:mode => :secondary, :tag_sets => [{'dc' => 'nyc'}])

Parameters:

preference (Hash) (defaults to: {}) —
The server preference.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/server_selector.rb', line 73


def get(preference = {})
  return preference if PREFERENCES.values.include?(preference.class)

  Mongo::Lint.validate_underscore_read_preference(preference)
  PREFERENCES.fetch((preference[:mode] || :primary).to_sym).new(preference)
end

#primary

Returns the primary server selector.

A call to this method is equivalent to get(mode: <code>:primary</code>), except the resulting server selector object is cached and not recreated each time.

Since:

2.0.0

[ GitHub ]

# File 'lib/mongo/server_selector.rb', line 86


def primary
  @primary ||= get(mode: :primary)
end