.. function:: setWHashedPerturbation(value)
+ .. versionadded:: 2.0.0
+ Before 2.0.0 this function was misspelled as ``setWHashedPerturbation``
+
Set the hash perturbation value to be used in the whashed policy instead of a random one, allowing to have consistent whashed results on different instances.
+.. function:: setWHashedPertubation(value)
+
+ .. deprecated:: 2.0.0
+ Before 2.0.0 this function was misspelled, see :func:`setWHashedPerturbation`
+
Since 1.5.0, a bounded-load version is also supported, trying to prevent one server from receiving much more queries than intended, even if the distribution of queries is not perfect. This "weighted hashing with bounded loads" algorithm is enabled by setting :func:`setWeightedBalancingFactor` to a value other than 0, which is the default. This value is the maximum number of outstanding queries that a given server can have at a given time, as a ratio of the total number of outstanding queries for all the active servers in the pool, pondered by the weight of the server.
The algorithm will try to select a server based on the hash of the qname, as is done when no bounded-load is set, but will disqualify all servers that have more outstanding queries than intended times the factor, until a suitable server is found. The higher the factor, the more imbalance between the servers is allowed.