This is the heart of the scalability change for services in libnetwork.
The present routing mesh adds load-balancing rules for a network to
every container connected to the network. This newer approach creates a
load-balancing endpoint per network per node. For every service on a
network, libnetwork assigns the VIP of the service to the endpoint's
interface as an alias. This endpoint must have a unique IP address in
order to route return traffic to it. Traffic destined for a service's
VIP arrives at the load-balancing endpoint on the VIP and from there,
Linux load balances it among backend destinations while SNATing said
traffic to the endpoint's unique IP address.
The net result of this scheme is that each node in a swarm need only
have one set of load balancing state per service instead of one per
container on the node. This scheme is very similar to how services
currently operate on Windows nodes in libnetwork. It (as with Windows
nodes) costs the use of extra IP addresses in a network (one per node)
and an extra network hop in the stack, although, always in the stack
local to the container.
In order to prevent existing deployments from suddenly failing if they
failed to allocate sufficient address space to include per-node
load-balancing endpoint IP addresses, this patch preserves the existing
functionality and activates the new functionality on a per-network
basis depending on whether the network has a load-balancing endpoint.
Eventually, moby should always set this option when creating new
networks and should only omit it for networks created as part of a swarm
that are not marked to use endpoint load balancing.
This patch also normalizes the code to treat "load" and "balancer"
as two separate words from the perspectives of variable/function naming.
This means that the 'b' in "balancer" must be capitalized.
Signed-off-by: Chris Telfer <ctelfer@docker.com>
1. Base work was done by msabansal and nwoodmsft
from : https://github.com/msabansal/docker/tree/overlay
2. reorganized under drivers/windows/overlay and rebased to
libnetwork master
3. Porting overlay common fixes to windows driver
* 46f525c
* ba8714e
* 6368406
4. Windows Service Discovery changes for swarm-mode
5. renaming default windows ipam drivers as "windows"
Signed-off-by: Madhu Venugopal <madhu@docker.com>
Signed-off-by: msabansal <sabansal@microsoft.com>
Signed-off-by: nwoodmsft <Nicholas.Wood@microsoft.com>
This also allows pubslied services to be accessible from containers on bridge
networks on the host
Signed-off-by: Santhosh Manohar <santhosh@docker.com>
When leaving the entire gossip cluster or when leaving a network
specific gossip cluster, we may not have had a chance to cleanup service
bindings by way of gossip updates due to premature closure of gossip
channel. Make sure to cleanup all service bindings since we are not
participating in the cluster any more.
Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>
Ingress load balancer is achieved via a service sandbox which acts as
the proxy to translate incoming node port requests and mapping that to a
service entry. Once the right service is identified, the same internal
loadbalancer implementation is used to load balance to the right backend
instance.
Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>
This PR adds support for loadbalancing across a group of endpoints that
share the same service configuration as passed in by
`OptionService`. The loadbalancer is implemented using ipvs with just
round robin scheduling supported for now.
Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>
