docs: Removal of Consul vs ZooKeeper analysis (#10469)

* docs: Removal of Consul vs ZooKeeper

Although Consul does have a KV, we are not positioning Consul as a first class KV store versus other alternatives such as etcd or Zookeeper. Will remove this since this has not been updated with further analysis since this content was created.

* Removing from Zookeeper analysis Navbar
* Removing Zookeeper analysis from redirects

website/content/docs/intro/vs/zookeeper.mdx

@@ -1,68 +0,0 @@
----
-layout: docs
-page_title: 'Consul vs. ZooKeeper, doozerd, etcd'
-description: >-
-  ZooKeeper, doozerd, and etcd are all similar in their architecture. All three
-  have server nodes that require a quorum of nodes to operate (usually a simple
-  majority). They are strongly-consistent and expose various primitives that can
-  be used through client libraries within applications to build complex
-  distributed systems.
----
-
-# Consul vs. ZooKeeper, doozerd, etcd
-
-ZooKeeper, doozerd, and etcd are all similar in their architecture. All three have
-server nodes that require a quorum of nodes to operate (usually a simple majority).
-They are strongly-consistent and expose various primitives that can be used through
-client libraries within applications to build complex distributed systems.
-
-Consul also uses server nodes within a single datacenter. In each datacenter, Consul
-servers require a quorum to operate and provide strong consistency. However, Consul
-has native support for multiple datacenters as well as a more feature-rich gossip
-system that links server nodes and clients.
-
-All of these systems have roughly the same semantics when providing key/value storage:
-reads are strongly consistent and availability is sacrificed for consistency in the
-face of a network partition. However, the differences become more apparent when these
-systems are used for advanced cases.
-
-The semantics provided by these systems are attractive for building service discovery
-systems, but it's important to stress that these features must be built. ZooKeeper et
-al. provide only a primitive K/V store and require that application developers build
-their own system to provide service discovery. Consul, by contrast, provides an
-opinionated framework for service discovery and eliminates the guess-work and
-development effort. Clients simply register services and then perform discovery using
-a DNS or HTTP interface. Other systems require a home-rolled solution.
-
-A compelling service discovery framework must incorporate health checking and the
-possibility of failures as well. It is not useful to know that Node A provides the Foo
-service if that node has failed or the service crashed. Naive systems make use of
-heartbeating, using periodic updates and TTLs. These schemes require work linear
-to the number of nodes and place the demand on a fixed number of servers. Additionally,
-the failure detection window is at least as long as the TTL.
-
-ZooKeeper provides ephemeral nodes which are K/V entries that are removed when a client
-disconnects. These are more sophisticated than a heartbeat system but still have
-inherent scalability issues and add client-side complexity. All clients must maintain
-active connections to the ZooKeeper servers and perform keep-alives. Additionally, this
-requires "thick clients" which are difficult to write and often result in debugging
-challenges.
-
-Consul uses a very different architecture for health checking. Instead of only having
-server nodes, Consul clients run on every node in the cluster. These clients are part
-of a [gossip pool](/docs/internals/gossip) which serves several functions,
-including distributed health checking. The gossip protocol implements an efficient
-failure detector that can scale to clusters of any size without concentrating the work
-on any select group of servers. The clients also enable a much richer set of health
-checks to be run locally, whereas ZooKeeper ephemeral nodes are a very primitive check
-of liveness. With Consul, clients can check that a web server is returning 200 status
-codes, that memory utilization is not critical, that there is sufficient disk space,
-etc. The Consul clients expose a simple HTTP interface and avoid exposing the complexity
-of the system to clients in the same way as ZooKeeper.
-
-Consul provides first-class support for service discovery, health checking,
-K/V storage, and multiple datacenters. To support anything more than simple K/V storage,
-all these other systems require additional tools and libraries to be built on
-top. By using client nodes, Consul provides a simple API that only requires thin clients.
-Additionally, the API can be avoided entirely by using configuration files and the
-DNS interface to have a complete service discovery solution with no development at all.

website/data/docs-nav-data.json

@@ -13,10 +13,6 @@
             "title": "Overview",
             "path": "intro/vs"
           },
-          {
-            "title": "ZooKeeper, doozerd, etcd",
-            "path": "intro/vs/zookeeper"
-          },
           {
             "title": "Chef, Puppet, etc.",
             "path": "intro/vs/chef-puppet"
@@ -991,4 +987,4 @@
     "path": "guides",
     "hidden": true
   }
-]
+]

website/redirects.next.js

@@ -255,11 +255,6 @@ module.exports = [
   },
   { source: '/intro', destination: '/docs/intro', permanent: true },
   { source: '/intro/vs', destination: '/docs/intro/vs', permanent: true },
-  {
-    source: '/intro/vs/zookeeper',
-    destination: '/docs/intro/vs/zookeeper',
-    permanent: true,
-  },
   {
     source: '/intro/vs/chef-puppet',
     destination: '/docs/intro/vs/chef-puppet',