.alter query weak consistency policy

The command sets the cluster query weak consistency policy, overriding the current policy, and then returns the updated policy. The updated policy can be later viewed using the show command. If not altered, the default policy applies.

Syntax

This command has two flavors:

• .alter cluster policy query_weak_consistency PolicyObject
• .alter-merge cluster policy query_weak_consistency PolicyObject

The first flavor expects a complete JSON (that includes all policy properties), and any property that is omitted, will be set to its default. The second flavor may receive a subset of the policy properties, and only those will be modified (while the rest remain untouched). Examples will follow.

Arguments

PolicyObject - a JSON policy object, see the query weak consistency policy for policy properties (also shown in the examples below).

Result

JSON serialization of the updated query weak consistency policy object

Examples

alter

alter command:

.alter cluster policy query_weak_consistency ```{
   "PercentageOfNodes": 10,
   "MinimumNumberOfNodes": 2,
   "MaximumNumberOfNodes": 20,
   "SuperSlackerNumberOfNodesThreshold": 5,
   "EnableMetadataPrefetch": false,
   "MaximumLagAllowedInMinutes": 10,
   "RefreshPeriodInSeconds": 300
   }```

Output

PolicyName	EntityName	Policy	ChildEntities	EntityType
QueryWeakConsistencyPolicy		{"PercentageOfNodes": 10, "MinimumNumberOfNodes": 2, "MaximumNumberOfNodes": 20, "SuperSlackerNumberOfNodesThreshold": 5, "EnableMetadataPrefetch": false, "MaximumLagAllowedInMinutes": 10, "RefreshPeriodInSeconds": 300}		Cluster

For demonstrating the alter-merge, we will assume the following policy is set prior to executing the command:

{
  "PercentageOfNodes": 20,
  "MinimumNumberOfNodes": 10,
  "MaximumNumberOfNodes": 100, 
  "SuperSlackerNumberOfNodesThreshold": 30,
  "EnableMetadataPrefetch": false,
  "MaximumLagAllowedInMinutes": 5,
  "RefreshPeriodInSeconds": 30
}

alter-merge

alter-merge command:

.alter-merge cluster policy query_weak_consistency @'{"PercentageOfNodes": 30, "MaximumLagAllowedInMinutes": 15}'

Output

PolicyName	EntityName	Policy	ChildEntities	EntityType
QueryWeakConsistencyPolicy		{"PercentageOfNodes": 30, "MinimumNumberOfNodes": 10, "MaximumNumberOfNodes": 100, "SuperSlackerNumberOfNodesThreshold": 30, "EnableMetadataPrefetch": false, "MaximumLagAllowedInMinutes": 15, "RefreshPeriodInSeconds": 30}		Cluster

As can be seen, only PercentageOfNodes and MaximumLagAllowedInMinutes were modified (whereas if the alter command was used instead, the remaining properties would be also modified, and set to their defaults).