loadbalancer
A registry of load balancers currently in use.
A registry of load balancers currently in use.
This class is thread-safe.
TwitterServer's "/admin/balancers.json" admin endpoint.
BalancerRegistry$.get()
A specialized ServiceFactory which admits that it backs a concrete endpoint.
A specialized ServiceFactory which admits that it backs a concrete endpoint. The extra information and functionality provided here is used by Finagle's load balancers.
A thin interface around a Balancer's constructor that allows Finagle to pass in context from the stack to the balancers at construction time.
A thin interface around a Balancer's constructor that allows Finagle to pass in context from the stack to the balancers at construction time.
The user guide for more details.
Balancers for a collection of available balancers.
Information about a load balancer.
Information about a load balancer.
This class is thread-safe and while the class itself is immutable, it proxies data from a Balancer which may be mutable.
TwitterServer's "/admin/balancers.json" admin endpoint.
While this exception is safe to retry, the assumption used here is that the underlying situation will not change soon enough to make a retry worthwhile as retrying is most likely to eat up the entire budget.
The behavior the load balancer should take when none of its nodes have a com.twitter.finagle.Status of Open.
The behavior the load balancer should take when none of its nodes have a com.twitter.finagle.Status of Open.
The default behavior is WhenNoNodesOpen.PickOne and can be customized on a client through LoadBalancerFactory.WhenNoNodesOpenParam:
import com.twitter.finagle.loadbalancer.LoadBalancerFactory.WhenNoNodesOpenParam import com.twitter.finagle.loadbalancer.WhenNoNodesOpen import com.twitter.finagle.Http Http.client .configured(WhenNoNodesOpenParam(WhenNoNodesOpen.FailFast))
WhenNoNodesOpens for Java friendly API.
the user guide.
Constructor methods for various load balancers.
Constructor methods for various load balancers. The methods take balancer
specific parameters and return a LoadBalancerFactory that allows you
to easily inject a balancer into the Finagle client stack via the
withLoadBalancer method.
configuring a client with a load balancer
$Protocol.client .withLoadBalancer(Balancers.aperture()) .newClient(...)
The user guide for more details.
A LoadBalancerFactory proxy which instantiates the underlying based on flags (see flags.scala for applicable flags).
Exposes a Stack.Module which composes load balancing into the respective Stack.
Exposes a Stack.Module which composes load balancing into the respective Stack. This is mixed in by default into Finagle's com.twitter.finagle.client.StackClient. The only necessary configuration is a LoadBalancerFactory.Dest which represents a changing collection of addresses that is load balanced over.
Returns the default process global Address ordering as set via
defaultAddressOrdering.
Returns the default process global Address ordering as set via
defaultAddressOrdering. If no value is set, Address.HashOrdering
is used with the assumption that hosts resolved via Finagle provide the
load balancer with resolved InetAddresses. If a separate resolution process
is used, outside of Finagle, the default ordering should be overridden.
Set the default Address ordering for the entire process (outside of clients which override it).
Set the default Address ordering for the entire process (outside of clients which override it).
LoadBalancerFactory.AddressOrdering for more info.
A GlobalFlag that changes the default balancer for every client in the process.
A GlobalFlag that changes the default balancer for every client in the process. Valid choices are ['heap', 'choice', and 'aperture'].
To configure the load balancer on a per-client granularity instead, use the
withLoadBalancer method like so:
{{ val balancer = Balancers.aperture(...) $Protocol.client.withLoadBalancer(balancer) }}
Returns the default process global LoadBalancerFactory as set via
defaultBalancerFactory.
Set the default LoadBalancerFactory for the entire process (outside of clients which override it).
Set the default LoadBalancerFactory for the entire process (outside of clients which override it).
LoadBalancerFactory.Param for more info.
A GlobalFlag which allows the configuration of per host (or endpoint) stats to be toggled.
A GlobalFlag which allows the configuration of per host (or endpoint) stats to be toggled. Note, these are off by default because they tend to be expensive, especially when the size of the destination cluster is large. However, they can be quite useful for debugging.
This package implements client side load balancing algorithms.
As an end-user, see the Balancers API to create instances which can be used to configure a Finagle client with various load balancing strategies.
As an implementor, each algorithm gets its own subdirectory and is exposed via the Balancers object. Several convenient traits are provided which factor out common behavior and can be mixed in (i.e. Balancer, DistributorT, NodeT, and Updating).