documentation: fix typo "a etcd" -> "an etcd"

"a" is not a correct article for "etcd".

Documentation/backward_compatibility.md

@@ -32,7 +32,7 @@ The consistent flag for read operations is removed in etcd 2.0.0. The normal rea
 
 The read consistency guarantees are:
 
-The consistent read guarantees the sequential consistency within one client that talks to one etcd server. Read/Write from one client to one etcd member should be observed in order. If one client write a value to a etcd server successfully, it should be able to get the value out of the server immediately. 
+The consistent read guarantees the sequential consistency within one client that talks to one etcd server. Read/Write from one client to one etcd member should be observed in order. If one client write a value to an etcd server successfully, it should be able to get the value out of the server immediately. 
 
 Each etcd member will proxy the request to leader and only return the result to user after the result is applied on the local member. Thus after the write succeed, the user is guaranteed to see the value on the member it sent the request to.
 

Documentation/discovery_protocol.md

@@ -14,7 +14,7 @@ The idea of discovery protocol is to use an internal etcd cluster to coordinate
 
 In the following example workflow, we will list each step of protocol in curl format for ease of understanding.
 
-By convention the etcd discovery protocol uses the key prefix `_etcd/registry`. If `http://example.com` hosts a etcd cluster for discovery service, a full URL to discovery keyspace will be `http://example.com/v2/keys/_etcd/registry`. We will use this as the URL prefix in the example.
+By convention the etcd discovery protocol uses the key prefix `_etcd/registry`. If `http://example.com` hosts an etcd cluster for discovery service, a full URL to discovery keyspace will be `http://example.com/v2/keys/_etcd/registry`. We will use this as the URL prefix in the example.
 
 ### Creating a New Discovery Token
 

Documentation/proxy.md

@@ -66,7 +66,7 @@ etcd -proxy on \
 
 ## Fallback to proxy mode with discovery service
 
-If you bootstrap a etcd cluster using [discovery service][discovery-service] with more than the expected number of etcd members, the extra etcd processes will fall back to being `readwrite` proxies by default. They will forward the requests to the cluster as described above. For example, if you create a discovery url with `size=5`, and start ten etcd processes using that same discovery url, the result will be a cluster with five etcd members and five proxies. Note that this behaviour can be disabled with the `proxy-fallback` flag.
+If you bootstrap an etcd cluster using [discovery service][discovery-service] with more than the expected number of etcd members, the extra etcd processes will fall back to being `readwrite` proxies by default. They will forward the requests to the cluster as described above. For example, if you create a discovery url with `size=5`, and start ten etcd processes using that same discovery url, the result will be a cluster with five etcd members and five proxies. Note that this behaviour can be disabled with the `proxy-fallback` flag.
 
 ## Promote a proxy to a member of etcd cluster
 

etcdserver/server.go

@@ -134,7 +134,7 @@ type Server interface {
 	UpdateMember(ctx context.Context, updateMemb Member) error
 
 	// ClusterVersion is the cluster-wide minimum major.minor version.
-	// Cluster version is set to the min version that a etcd member is
+	// Cluster version is set to the min version that an etcd member is
 	// compatible with when first bootstrap.
 	//
 	// ClusterVersion is nil until the cluster is bootstrapped (has a quorum).

tools/functional-tester/README.md

@@ -1,6 +1,6 @@
 # etcd functional test suite
 
-etcd functional test suite tests the functionality of a etcd cluster with a focus on failure resistance under high pressure. It sets up an etcd cluster and inject failures into the cluster by killing the process or isolate the network of the process. It expects the etcd cluster to recover within a short amount of time after fixing the fault.
+etcd functional test suite tests the functionality of an etcd cluster with a focus on failure resistance under high pressure. It sets up an etcd cluster and inject failures into the cluster by killing the process or isolate the network of the process. It expects the etcd cluster to recover within a short amount of time after fixing the fault.
 
 etcd functional test suite has two components: etcd-agent and etcd-tester. etcd-agent runs on every test machines and etcd-tester is a single controller of the test. etcd-tester controls all the etcd-agent to start etcd clusters and simulate various failure cases.