PERL-799: parse Logical session timeout from isMaster

lib/MongoDB/_Server.pm

@@ -34,6 +34,7 @@ use Types::Standard qw(
     HashRef
     Str
     Num
+    Maybe
 );
 use List::Util qw/first/;
 use Time::HiRes qw/time/;
@@ -251,6 +252,30 @@ sub _build_is_writable {
     return !! grep { $type eq $_ } qw/Standalone RSPrimary Mongos/;
 }
 
+has is_data_bearing => (
+    is => 'lazy',
+    isa => Bool,
+    builder => "_build_is_data_bearing",
+);
+
+sub _build_is_data_bearing {
+    my ( $self ) = @_;
+    my $type = $self->type;
+    return !! grep { $type eq $_ } qw/Standalone RSPrimary RSSecondary Mongos/;
+}
+
+# logicalSessionTimeoutMinutes can be not set by a client
+has logical_session_timeout_minutes => (
+    is => 'lazy',
+    isa => Maybe [NonNegNum],
+    builder => "_build_logical_session_timeout_minutes",
+);
+
+sub _build_logical_session_timeout_minutes {
+    my ( $self ) = @_;
+    return $self->is_master->{logicalSessionTimeoutMinutes} || undef;
+}
+
 sub updated_since {
     my ( $self, $time ) = @_;
     return( ($self->last_update_time - $time) > 0 );

lib/MongoDB/_Topology.pm

@@ -47,7 +47,7 @@ use Types::Standard qw(
 );
 use MongoDB::_Server;
 use Config;
-use List::Util qw/first max/;
+use List::Util qw/first max min/;
 use Safe::Isa;
 use Time::HiRes qw/time usleep/;
 use Try::Tiny;
@@ -127,6 +127,13 @@ has local_threshold_sec => (
     isa => Num,
 );
 
+has logical_session_timeout_minutes => (
+    is => 'ro',
+    default => undef,
+    writer => '_set_logical_session_timeout_minutes',
+    isa => Maybe [NonNegNum],
+);
+
 has next_scan_time => (
     is      => 'ro',
     default => sub { time() },
@@ -552,6 +559,24 @@ sub _check_wire_versions {
     return;
 }
 
+sub _update_ls_timeout_minutes {
+    my ( $self, $new_server ) = @_;
+
+    my @data_bearing_servers = grep { $_->is_data_bearing } $self->all_servers;
+    my $timeout = min map {
+        # use -1 as a flag to prevent undefined warnings
+        defined $_->logical_session_timeout_minutes
+          ? $_->logical_session_timeout_minutes
+          : -1
+    } @data_bearing_servers;
+    # min will return undef if the array is empty
+    if ( defined $timeout && $timeout < 0 ) {
+        $timeout = undef;
+    }
+    $self->_set_logical_session_timeout_minutes( $timeout );
+    return;
+}
+
 sub _check_staleness_compatibility {
     my ($self, $read_pref) = @_;
     my $max_staleness_sec = $read_pref ? $read_pref->max_staleness_seconds : -1;
@@ -997,6 +1022,8 @@ sub _update_topology_from_server_desc {
     # if link is still around, tag it with server specifics
     $self->_update_link_metadata( $address, $new_server );
 
+    $self->_update_ls_timeout_minutes( $new_server );
+
     return $new_server;
 }
 

t/data/SDAM/README.rst

@@ -6,27 +6,6 @@ The YAML and JSON files in this directory tree are platform-independent tests
 that drivers can use to prove their conformance to the
 Server Discovery And Monitoring Spec.
 
-Converting to JSON
-------------------
-
-The tests are written in YAML
-because it is easier for humans to write and read,
-and because YAML includes a standard comment format.
-A JSONified version of each YAML file is included in this repository.
-Whenever you change the YAML, re-convert to JSON.
-One method to convert to JSON is with
-`jsonwidget-python <http://jsonwidget.org/wiki/Jsonwidget-python>`_::
-
-    pip install PyYAML urwid jsonwidget
-    make
-
-Or instead of "make":
-
-    for i in `find . -iname '*.yml'`; do
-        echo "${i%.*}"
-        jwc yaml2json $i > ${i%.*}.json
-    done
-
 Version
 -------
 
@@ -71,6 +50,8 @@ processing the responses in the phases so far. It has the following keys:
 - setName: A string with the expected replica set name, or null.
 - servers: An object whose keys are addresses like "a:27017", and whose values
   are "server" objects.
+- logicalSessionTimeoutMinutes: null or an integer.
+- compatible: absent or a bool.
 
 A "server" object represents a correct ServerDescription within the client's
 current TopologyDescription. It has the following keys:
@@ -79,24 +60,56 @@ current TopologyDescription. It has the following keys:
 - setName: A string with the expected replica set name, or null.
 - setVersion: absent or an integer.
 - electionId: absent, null, or an ObjectId.
+- logicalSessionTimeoutMinutes: absent, null, or an integer.
+- minWireVersion: absent or an integer.
+- maxWireVersion: absent or an integer.
 
 Use as unittests
 ----------------
 
+Mocking
+~~~~~~~
+
 Drivers should be able to test their server discovery and monitoring logic
 without any network I/O, by parsing ismaster responses from the test file
 and passing them into the driver code. Parts of the client and monitoring
 code may need to be mocked or subclassed to achieve this. `A reference
 implementation for PyMongo 3.x is available here
 <https://github.com/mongodb/mongo-python-driver/blob/3.0-dev/test/test_discovery_and_monitoring.py>`_.
 
+Initialization
+~~~~~~~~~~~~~~
+
 For each file, create a fresh client object initialized with the file's "uri".
 
+All files in the "single" directory include a connection string with one host
+and no "replicaSet" option.
+Set the client's initial TopologyType to Single, however that is achieved using the client's API.
+(The spec says "The user MUST be able to set the initial TopologyType to Single"
+without specifying how.)
+
+All files in the "sharded" directory include a connection string with multiple hosts
+and no "replicaSet" option.
+Set the client's initial TopologyType to Unknown or Sharded, depending on the client's API.
+
+All files in the "rs" directory include a connection string with a "replicaSet" option.
+Set the client's initial TopologyType to ReplicaSetNoPrimary.
+(For most clients, parsing a connection string with a "replicaSet" option
+automatically sets the TopologyType to ReplicaSetNoPrimary.)
+
+Test Phases
+~~~~~~~~~~~
+
 For each phase in the file, parse the "responses" array.
 Pass in the responses in order to the driver code.
 If a response is the empty object `{}`, simulate a network error.
 
 Once all responses are processed, assert that the phase's "outcome" object
 is equivalent to the driver's current TopologyDescription.
 
+Some fields such as "logicalSessionTimeoutMinutes" or "compatible" were added
+later and haven't been added to all test files. If these fields are present,
+test that they are equivalent to the fields of the driver's current
+TopologyDescription.
+
 Continue until all phases have been executed.

t/data/SDAM/rs/compatible.json

@@ -0,0 +1,55 @@
+{
+  "description": "Replica set member with large maxWireVersion",
+  "uri": "mongodb://a,b/?replicaSet=rs",
+  "phases": [
+    {
+      "responses": [
+        [
+          "a:27017",
+          {
+            "ok": 1,
+            "ismaster": true,
+            "setName": "rs",
+            "hosts": [
+              "a:27017",
+              "b:27017"
+            ],
+            "minWireVersion": 0,
+            "maxWireVersion": 6
+          }
+        ],
+        [
+          "b:27017",
+          {
+            "ok": 1,
+            "ismaster": false,
+            "secondary": true,
+            "setName": "rs",
+            "hosts": [
+              "a:27017",
+              "b:27017"
+            ],
+            "minWireVersion": 0,
+            "maxWireVersion": 1000
+          }
+        ]
+      ],
+      "outcome": {
+        "servers": {
+          "a:27017": {
+            "type": "RSPrimary",
+            "setName": "rs"
+          },
+          "b:27017": {
+            "type": "RSSecondary",
+            "setName": "rs"
+          }
+        },
+        "topologyType": "ReplicaSetWithPrimary",
+        "setName": "rs",
+        "logicalSessionTimeoutMinutes": null,
+        "compatible": true
+      }
+    }
+  ]
+}

t/data/SDAM/rs/compatible.yml

@@ -0,0 +1,41 @@
+description: "Replica set member with large maxWireVersion"
+uri: "mongodb://a,b/?replicaSet=rs"
+phases: [
+    {
+        responses: [
+                ["a:27017", {
+                    ok: 1,
+                    ismaster: true,
+                    setName: "rs",
+                    hosts: ["a:27017", "b:27017"],
+                    minWireVersion: 0,
+                    maxWireVersion: 6
+                }],
+                ["b:27017", {
+                    ok: 1,
+                    ismaster: false,
+                    secondary: true,
+                    setName: "rs",
+                    hosts: ["a:27017", "b:27017"],
+                    minWireVersion: 0,
+                    maxWireVersion: 1000
+                }]
+        ],
+        outcome: {
+            servers: {
+                "a:27017": {
+                    type: "RSPrimary",
+                    setName: "rs"
+                },
+                "b:27017": {
+                    type: "RSSecondary",
+                    setName: "rs"
+                }
+            },
+            topologyType: "ReplicaSetWithPrimary",
+            setName: "rs",
+            logicalSessionTimeoutMinutes: null,
+            compatible: true
+        }
+    }
+]

t/data/SDAM/rs/discover_arbiters.json

@@ -1,38 +1,41 @@
 {
-    "description": "Discover arbiters", 
-    "phases": [
-        {
-            "outcome": {
-                "servers": {
-                    "a:27017": {
-                        "setName": "rs", 
-                        "type": "RSPrimary"
-                    }, 
-                    "b:27017": {
-                        "setName": null, 
-                        "type": "Unknown"
-                    }
-                }, 
-                "setName": "rs", 
-                "topologyType": "ReplicaSetWithPrimary"
-            }, 
-            "responses": [
-                [
-                    "a:27017", 
-                    {
-                        "arbiters": [
-                            "b:27017"
-                        ], 
-                        "hosts": [
-                            "a:27017"
-                        ], 
-                        "ismaster": true, 
-                        "ok": 1, 
-                        "setName": "rs"
-                    }
-                ]
-            ]
-        }
-    ], 
-    "uri": "mongodb://a/?replicaSet=rs"
+  "description": "Discover arbiters",
+  "uri": "mongodb://a/?replicaSet=rs",
+  "phases": [
+    {
+      "responses": [
+        [
+          "a:27017",
+          {
+            "ok": 1,
+            "ismaster": true,
+            "hosts": [
+              "a:27017"
+            ],
+            "arbiters": [
+              "b:27017"
+            ],
+            "setName": "rs",
+            "minWireVersion": 0,
+            "maxWireVersion": 6
+          }
+        ]
+      ],
+      "outcome": {
+        "servers": {
+          "a:27017": {
+            "type": "RSPrimary",
+            "setName": "rs"
+          },
+          "b:27017": {
+            "type": "Unknown",
+            "setName": null
+          }
+        },
+        "topologyType": "ReplicaSetWithPrimary",
+        "logicalSessionTimeoutMinutes": null,
+        "setName": "rs"
+      }
+    }
+  ]
 }

t/data/SDAM/rs/discover_arbiters.yml

@@ -13,7 +13,9 @@ phases: [
                     ismaster: true,
                     hosts: ["a:27017"],
                     arbiters: ["b:27017"],
-                    setName: "rs"
+                    setName: "rs",
+                    minWireVersion: 0,
+                    maxWireVersion: 6
                 }]
         ],
 
@@ -33,8 +35,8 @@ phases: [
                     setName:
                 }
             },
-
             topologyType: "ReplicaSetWithPrimary",
+            logicalSessionTimeoutMinutes: null,
             setName: "rs"
         }
     }