Merge pull request #40214 from bergerhoffer/OSDOCS-3138

OSDOCS-3138: Removing scheduler policy

Author: bergerhoffer

_topic_maps/_topic_map.yml

@@ -1769,8 +1769,6 @@ Topics:
   Topics:
   - Name: About pod placement using the scheduler
     File: nodes-scheduler-about
-  - Name: Configuring the default scheduler to control pod placement
-    File: nodes-scheduler-default
   - Name: Scheduling pods using a scheduler profile
     File: nodes-scheduler-profiles
   - Name: Placing pods relative to other pods using pod affinity and anti-affinity rules

modules/nodes-nodes-working-master-schedulable.adoc

@@ -49,8 +49,6 @@ metadata:
   uid: a636d30a-d377-11e9-88d4-0a60097bee62
 spec:
   mastersSchedulable: false <1>
-  policy:
-    name: ""
 status: {}
 ----
 <1> Set to `true` to allow control plane nodes to be schedulable, or `false` to

modules/nodes-scheduler-default-about.adoc

@@ -9,110 +9,22 @@
 The existing generic scheduler is the default platform-provided scheduler
 _engine_ that selects a node to host the pod in a three-step operation:
 
-
-Filters the Nodes::
+Filters the nodes::
 The available nodes are filtered based on the constraints or requirements
 specified. This is done by running each node through the list of filter
-functions called _predicates_.
+functions called _predicates_, or _filters_.
 
-Prioritize the Filtered List of Nodes::
-This is achieved by passing each node through a series of priority_ functions
+Prioritizes the filtered list of nodes::
+This is achieved by passing each node through a series of _priority_, or _scoring_, functions
 that assign it a score between 0 - 10, with 0 indicating a bad fit and 10
 indicating a good fit to host the pod. The scheduler configuration can also take
-in a simple _weight_ (positive numeric value) for each priority function. The
-node score provided by each priority function is multiplied by the weight
-(default weight for most priorities is 1) and then combined by adding the scores for each node
-provided by all the priorities. This weight attribute can be used by
-administrators to give higher importance to some priorities.
+in a simple _weight_ (positive numeric value) for each scoring function. The
+node score provided by each scoring function is multiplied by the weight
+(default weight for most scores is 1) and then combined by adding the scores for each node
+provided by all the scores. This weight attribute can be used by
+administrators to give higher importance to some scores.
 
-Select the Best Fit Node::
+Selects the best fit node::
 The nodes are sorted based on their scores and the node with the highest score
 is selected to host the pod. If multiple nodes have the same high score, then
 one of them is selected at random.
-
-[id="nodes-scheduler-default-about-understanding_{context}"]
-== Understanding Scheduler Policy
-
-The selection of the predicate and priorities defines the policy for the scheduler.
-
-The scheduler configuration file is a JSON file, which must be named `policy.cfg`, that specifies the predicates and priorities the scheduler
-will consider.
-
-In the absence of the scheduler policy file, the default scheduler behavior is used.
-
-// we are working on how to configures this in 4.0 right now in https://github.com/openshift/api/pull/181
-
-[IMPORTANT]
-====
-The predicates and priorities defined in
-the scheduler configuration file completely override the default scheduler
-policy. If any of the default predicates and priorities are required,
-you must explicitly specify the functions in the policy configuration.
-====
-
-.Sample scheduler config map
-[source,yaml]
-----
-apiVersion: v1
-data:
-  policy.cfg: |
-    {
-        "kind" : "Policy",
-        "apiVersion" : "v1",
-        "predicates" : [
-                {"name" : "MaxGCEPDVolumeCount"},
-                {"name" : "GeneralPredicates"}, <1>
-                {"name" : "MaxAzureDiskVolumeCount"},
-                {"name" : "MaxCSIVolumeCountPred"},
-                {"name" : "CheckVolumeBinding"},
-                {"name" : "MaxEBSVolumeCount"},
-                {"name" : "MatchInterPodAffinity"},
-                {"name" : "CheckNodeUnschedulable"},
-                {"name" : "NoDiskConflict"},
-                {"name" : "NoVolumeZoneConflict"},
-                {"name" : "PodToleratesNodeTaints"}
-                ],
-        "priorities" : [
-                {"name" : "LeastRequestedPriority", "weight" : 1},
-                {"name" : "BalancedResourceAllocation", "weight" : 1},
-                {"name" : "ServiceSpreadingPriority", "weight" : 1},
-                {"name" : "NodePreferAvoidPodsPriority", "weight" : 1},
-                {"name" : "NodeAffinityPriority", "weight" : 1},
-                {"name" : "TaintTolerationPriority", "weight" : 1},
-                {"name" : "ImageLocalityPriority", "weight" : 1},
-                {"name" : "SelectorSpreadPriority", "weight" : 1},
-                {"name" : "InterPodAffinityPriority", "weight" : 1},
-                {"name" : "EqualPriority", "weight" : 1}
-                ]
-    }
-kind: ConfigMap
-metadata:
-  creationTimestamp: "2019-09-17T08:42:33Z"
-  name: scheduler-policy
-  namespace: openshift-config
-  resourceVersion: "59500"
-  selfLink: /api/v1/namespaces/openshift-config/configmaps/scheduler-policy
-  uid: 17ee8865-d927-11e9-b213-02d1e1709840`
-----
-<1> The `GeneralPredicates` predicate represents the `PodFitsResources`, `HostName`, `PodFitsHostPorts`, and `MatchNodeSelector` predicates.
-Because you are not allowed to configure the same predicate multiple times, the `GeneralPredicates` predicate cannot be used alongside
-any of the four represented predicates.
-
-////
-.Typical predicate string
-----
-\n\t{\"name\" : \"<PredicateName>\", \"label\" : \"<label>\",  \"<condition>\" : \"<state>\"},
-----
-* `name` is the name of the predicate, such as `labelsPresence`.
-* `label` and `<label>` is the node label:value pair to match to apply the predicate, such `label:rack`.
-* `<condition>` and `<state>` is when the predicate should be applied, such as `presence:true`.
-
-.Typical priority string
-----
-\n\t{\"name\" : \"<PredicateName>\", \"label\" : \"<label>\",  \"<condition>\" : \"<state>\", \"weight\" : <weight>},
-----
-* `name` is the name of the priority, such as `labelsPresence`.
-* `label` and `<label>` is the node `label:value` pair to match to apply the priority, such `label:rack`.
-* `<condition>` and `<state>` is when the priority should be applied, such as `presence:true`.
-* `weight` and `<weight> is the numerical weight to apply to the priority.
-////