Finish replacing references to old etcd master branch.

Signed-off-by: James Blair <mail@jamesblair.net>

Author: jmhbnz

content/en/docs/v3.6/benchmarks/etcd-2-1-0-alpha-benchmarks.md

@@ -54,5 +54,5 @@ Bootstrap another machine and use the [hey HTTP benchmark tool][hey] to send req
 | 256               | 64                | all servers        | 1033      | 121.5 |
 | 256               | 256               | all servers        | 3061      | 119.3 |
 
-[hack-benchmark]: http://github.com/etcd-io/etcd/tree/master/hack/benchmark
+[hack-benchmark]: http://github.com/etcd-io/etcd/tree/main/hack/benchmark
 [hey]: http://github.com/rakyll/hey

content/en/docs/v3.6/benchmarks/etcd-3-demo-benchmarks.md

@@ -45,4 +45,4 @@ The performance is nearly the same as the one with empty server handler.
 The performance with empty server handler is not affected by one put. So the
 performance downgrade should be caused by storage package.
 
-[etcd-v3-benchmark]: http://github.com/etcd-io/etcd/tree/master/tools/benchmark
+[etcd-v3-benchmark]: http://github.com/etcd-io/etcd/tree/main/tools/benchmark

content/en/docs/v3.6/dev-guide/api_grpc_gateway.md

@@ -130,8 +130,8 @@ curl -L http://localhost:2379/v3/kv/put \
 Generated [Swagger][swagger] API definitions can be found at [rpc.swagger.json][swagger-doc].
 
 [api-ref]: ../api_reference_v3/
-[etcdctl]: http://github.com/etcd-io/etcd/tree/master/etcdctl
-[go-client]: http://github.com/etcd-io/etcd/tree/master/client/v3
+[etcdctl]: http://github.com/etcd-io/etcd/tree/main/etcdctl
+[go-client]: http://github.com/etcd-io/etcd/tree/main/client/v3
 [grpc]: http://www.grpc.io/
 [grpc-gateway]: http://github.com/grpc-ecosystem/grpc-gateway
 [json-mapping]: http://developers.google.com/protocol-buffers/docs/proto3#json

content/en/docs/v3.6/faq.md

@@ -158,15 +158,15 @@ etcd sends a snapshot of its complete key-value store to refresh slow followers
 [api-mvcc]: ../learning/api/#revisions
 [backend_commit_metrics]: ../metrics/#disk
 [backup]: ../op-guide/recovery/#snapshotting-the-keyspace
-[benchmark]: http://github.com/etcd-io/etcd/tree/master/tools/benchmark
+[benchmark]: http://github.com/etcd-io/etcd/tree/main/tools/benchmark
 [benchmark-result]: ../op-guide/performance/
 [chubby]: http://static.googleusercontent.com/media/research.google.com/en//archive/chubby-osdi06.pdf
 [fio]: http://github.com/axboe/fio
 [fio-blog-post]: http://www.ibm.com/cloud/blog/using-fio-to-tell-whether-your-storage-is-fast-enough-for-etcd
 [hardware-setup]: ../op-guide/hardware/
 [maintenance-compact]:  ../op-guide/maintenance/#history-compaction-v3-api-key-value-database
 [maintenance-defragment]: ../op-guide/maintenance/#defragmentation
-[maintenance-disarm]: http://github.com/etcd-io/etcd/blob/master/etcdctl/README.md#alarm-disarm
+[maintenance-disarm]: http://github.com/etcd-io/etcd/blob/main/etcdctl/README.md#alarm-disarm
 [new_issue]: http://github.com/etcd-io/etcd/issues/new
 [raft]: http://raft.github.io/raft.pdf
 [runtime reconfiguration]: ../op-guide/runtime-configuration/

content/en/docs/v3.6/integrations.md

@@ -6,7 +6,7 @@ description: A listing of etcd tools and client libraries
 
 ## Tools
 
-- [etcdctl](http://github.com/etcd-io/etcd/tree/master/etcdctl) - A command line client for etcd
+- [etcdctl](http://github.com/etcd-io/etcd/tree/main/etcdctl) - A command line client for etcd
 - [etcd-dump](http://npmjs.org/package/etcd-dump) - Command line utility for dumping/restoring etcd.
 - [etcd-fs](http://github.com/xetorthio/etcd-fs) - FUSE filesystem for etcd
 - [etcddir](http://github.com/rekby/etcddir) - Realtime sync etcd and local directory. Work with windows and linux.
@@ -27,8 +27,8 @@ The sections below list etcd client libraries by language.
 
 ### Go
 
-- [etcd/client/v3](http://github.com/etcd-io/etcd/tree/master/client/v3) - the officially maintained Go client for v3
-- [etcd/client/v2](http://github.com/etcd-io/etcd/tree/master/client/v2) - the officially maintained Go client for v2
+- [etcd/client/v3](http://github.com/etcd-io/etcd/tree/main/client/v3) - the officially maintained Go client for v3
+- [etcd/client/v2](http://github.com/etcd-io/etcd/tree/main/client/v2) - the officially maintained Go client for v2
 - [go-etcd](http://github.com/coreos/go-etcd) - the deprecated official client. May be useful for older (<2.0.0) versions of etcd.
 - [encWrapper](http://github.com/lumjjb/etcd/tree/enc_wrapper/clientwrap/encwrapper) - encWrapper is an encryption wrapper for the etcd client Keys API/KV.
 
@@ -161,7 +161,7 @@ The sections below list etcd client libraries by language.
 
 ## Projects using etcd
 
-- [etcd Raft users](http://github.com/etcd-io/etcd/blob/master/raft/README.md#notable-users) - projects using etcd's raft library implementation.
+- [etcd Raft users](http://github.com/etcd-io/raft/blob/main/README.md#notable-users) - projects using etcd's raft library implementation.
 - [apache/celix](http://github.com/apache/celix) - an implementation of the OSGi specification adapted to C and C++
 - [binocarlos/yoda](http://github.com/binocarlos/yoda) - etcd + ZeroMQ
 - [blox/blox](http://github.com/blox/blox) - a collection of open source projects for container management and orchestration with AWS ECS

content/en/docs/v3.6/learning/api.md

@@ -480,10 +480,10 @@ message LeaseKeepAliveResponse {
 * ID - the lease that was refreshed with a new TTL.
 * TTL - the new time-to-live, in seconds, that the lease has remaining.
 
-[elections]: http://github.com/etcd-io/etcd/blob/master/client/v3/concurrency/election.go
+[elections]: http://github.com/etcd-io/etcd/blob/main/client/v3/concurrency/election.go
 [grpc-api]: ../../dev-guide/api_reference_v3/
-[grpc-service]: http://github.com/etcd-io/etcd/blob/master/api/etcdserverpb/rpc.proto
-[kv-proto]: http://github.com/etcd-io/etcd/blob/master/api/mvccpb/kv.proto
-[locks]: http://github.com/etcd-io/etcd/blob/master/client/v3/concurrency/mutex.go
+[grpc-service]: http://github.com/etcd-io/etcd/blob/main/api/etcdserverpb/rpc.proto
+[kv-proto]: http://github.com/etcd-io/etcd/blob/main/api/mvccpb/kv.proto
+[locks]: http://github.com/etcd-io/etcd/blob/main/client/v3/concurrency/mutex.go
 [mvcc]: http://en.wikipedia.org/wiki/Multiversion_concurrency_control
-[stm]: http://github.com/etcd-io/etcd/blob/master/client/v3/concurrency/stm.go
+[stm]: http://github.com/etcd-io/etcd/blob/main/client/v3/concurrency/stm.go

content/en/docs/v3.6/learning/why.md

@@ -112,8 +112,8 @@ Note that in the case of etcd keys, it can be locked efficiently because of the
 [curator]: http://curator.apache.org/
 [dbtester-comparison-results]: http://github.com/coreos/dbtester/tree/master/test-results/2018Q1-02-etcd-zookeeper-consul
 [etcd-commonname]: ../../op-guide/authentication/#using-tls-common-name
-[etcd-etcdctl-elect]: http://github.com/etcd-io/etcd/blob/master/etcdctl/README.md#elect-options-election-name-proposal
-[etcd-etcdctl-lock]: http://github.com/etcd-io/etcd/blob/master/etcdctl/README.md#lock-options-lockname-command-arg1-arg2-
+[etcd-etcdctl-elect]: http://github.com/etcd-io/etcd/blob/main/etcdctl/README.md#elect-options-election-name-proposal
+[etcd-etcdctl-lock]: http://github.com/etcd-io/etcd/blob/main/etcdctl/README.md#lock-options-lockname-command-arg1-arg2-
 [etcd-json]: ../../dev-guide/api_grpc_gateway/
 [etcd-linread]: ../api_guarantees/#isolation-level-and-consistency-of-replicas
 [etcd-mvcc]: ../data_model/
@@ -133,7 +133,7 @@ Note that in the case of etcd keys, it can be locked efficiently because of the
 [locksmith]: http://github.com/coreos/locksmith
 [newsql-leader]: http://dl.acm.org/citation.cfm?id=2960999
 [physicalclock]: http://web.archive.org/web/20190725151657/http://www.dainf.cefetpr.br/~tacla/SDII/PracticalUseOfClocks.pdf
-[production-users]: http://github.com/etcd-io/etcd/blob/master/ADOPTERS.md
+[production-users]: http://github.com/etcd-io/etcd/blob/main/ADOPTERS.md
 [spanner]: http://cloud.google.com/spanner/
 [spanner-roles]: http://cloud.google.com/spanner/docs/iam#roles
 [tidb]: http://github.com/pingcap/tidb

content/en/docs/v3.6/op-guide/clustering.md

@@ -497,4 +497,4 @@ To setup an etcd cluster with proxies of v2 API, please read the the [clustering
 [runtime-reconf-design]: ../runtime-reconf-design/
 [security-guide-dns-srv]: ../security/#notes-for-dns-srv
 [security-guide]: ../security/
-[tls-setup]: http://github.com/etcd-io/etcd/tree/master/hack/tls-setup
+[tls-setup]: http://github.com/etcd-io/etcd/tree/main/hack/tls-setup

content/en/docs/v3.6/op-guide/maintenance.md

@@ -49,11 +49,11 @@ Error:  rpc error: code = 11 desc = etcdserver: mvcc: required revision has been
 $ etcd --auto-compaction-retention=1
 ```
 
-[v3.0.0](http://github.com/etcd-io/etcd/blob/master/CHANGELOG-3.0.md) and [v3.1.0](http://github.com/etcd-io/etcd/blob/master/CHANGELOG-3.1.md) with `--auto-compaction-retention=10` run periodic compaction on v3 key-value store for every 10-hour. Compactor only supports periodic compaction. Compactor records latest revisions every 5-minute, until it reaches the first compaction period (e.g. 10-hour). In order to retain key-value history of last compaction period, it uses the last revision that was fetched before compaction period, from the revision records that were collected every 5-minute. When `--auto-compaction-retention=10`, compactor uses revision 100 for compact revision where revision 100 is the latest revision fetched from 10 hours ago. If compaction succeeds or requested revision has already been compacted, it resets period timer and starts over with new historical revision records (e.g. restart revision collect and compact for the next 10-hour period). If compaction fails, it retries in 5 minutes.
+[v3.0.0](http://github.com/etcd-io/etcd/blob/main/CHANGELOG-3.0.md) and [v3.1.0](http://github.com/etcd-io/etcd/blob/main/CHANGELOG-3.1.md) with `--auto-compaction-retention=10` run periodic compaction on v3 key-value store for every 10-hour. Compactor only supports periodic compaction. Compactor records latest revisions every 5-minute, until it reaches the first compaction period (e.g. 10-hour). In order to retain key-value history of last compaction period, it uses the last revision that was fetched before compaction period, from the revision records that were collected every 5-minute. When `--auto-compaction-retention=10`, compactor uses revision 100 for compact revision where revision 100 is the latest revision fetched from 10 hours ago. If compaction succeeds or requested revision has already been compacted, it resets period timer and starts over with new historical revision records (e.g. restart revision collect and compact for the next 10-hour period). If compaction fails, it retries in 5 minutes.
 
-[v3.2.0](http://github.com/etcd-io/etcd/blob/master/CHANGELOG-3.2.md) compactor runs [every hour](http://github.com/etcd-io/etcd/pull/7875). Compactor only supports periodic compaction. Compactor continues to record latest revisions every 5-minute. For every hour, it uses the last revision that was fetched before compaction period, from the revision records that were collected every 5-minute. That is, for every hour, compactor discards historical data created before compaction period. The retention window of compaction period moves to next hour. For instance, when hourly writes are 100 and `--auto-compaction-retention=10`, v3.1 compacts revision 1000, 2000, and 3000 for every 10-hour, while v3.2.x, v3.3.0, v3.3.1, and v3.3.2 compact revision 1000, 1100, and 1200 for every 1-hour. If compaction succeeds or requested revision has already been compacted, it resets period timer and removes used compacted revision from historical revision records (e.g. start next revision collect and compaction from previously collected revisions). If compaction fails, it retries in 5 minutes.
+[v3.2.0](http://github.com/etcd-io/etcd/blob/main/CHANGELOG-3.2.md) compactor runs [every hour](http://github.com/etcd-io/etcd/pull/7875). Compactor only supports periodic compaction. Compactor continues to record latest revisions every 5-minute. For every hour, it uses the last revision that was fetched before compaction period, from the revision records that were collected every 5-minute. That is, for every hour, compactor discards historical data created before compaction period. The retention window of compaction period moves to next hour. For instance, when hourly writes are 100 and `--auto-compaction-retention=10`, v3.1 compacts revision 1000, 2000, and 3000 for every 10-hour, while v3.2.x, v3.3.0, v3.3.1, and v3.3.2 compact revision 1000, 1100, and 1200 for every 1-hour. If compaction succeeds or requested revision has already been compacted, it resets period timer and removes used compacted revision from historical revision records (e.g. start next revision collect and compaction from previously collected revisions). If compaction fails, it retries in 5 minutes.
 
-In [v3.3.0](http://github.com/etcd-io/etcd/blob/master/CHANGELOG-3.3.md), [v3.3.1](http://github.com/etcd-io/etcd/blob/master/CHANGELOG-3.3.md), and [v3.3.2](http://github.com/etcd-io/etcd/blob/master/CHANGELOG-3.3.md), `--auto-compaction-mode=revision --auto-compaction-retention=1000` automatically `Compact` on `"latest revision" - 1000` every 5-minute (when latest revision is 30000, compact on revision 29000). For instance, `--auto-compaction-mode=periodic --auto-compaction-retention=72h` automatically `Compact` with 72-hour retention windown, for every 7.2-hour. For instance, `--auto-compaction-mode=periodic --auto-compaction-retention=30m` automatically `Compact` with 30-minute retention windown, for every 3-minute. Periodic compactor continues to record latest revisions for every 1/10 of given compaction period (e.g. 1-hour when `--auto-compaction-mode=periodic --auto-compaction-retention=10h`). For every 1/10 of given compaction period, compactor uses the last revision that was fetched before compaction period, to discard historical data. The retention window of compaction period moves for every 1/10 of given compaction period. For instance, when hourly writes are 100 and `--auto-compaction-retention=10`, v3.1 compacts revision 1000, 2000, and 3000 for every 10-hour, while v3.2.x, v3.3.0, v3.3.1, and v3.3.2 compact revision 1000, 1100, and 1200 for every 1-hour. Furthermore, when writes per minute are 1000, v3.3.0, v3.3.1, and v3.3.2 with `--auto-compaction-mode=periodic --auto-compaction-retention=30m` compact revision 30000, 33000, and 36000, for every 3-minute with more finer granularity.
+In [v3.3.0](http://github.com/etcd-io/etcd/blob/main/CHANGELOG-3.3.md), [v3.3.1](http://github.com/etcd-io/etcd/blob/main/CHANGELOG-3.3.md), and [v3.3.2](http://github.com/etcd-io/etcd/blob/main/CHANGELOG-3.3.md), `--auto-compaction-mode=revision --auto-compaction-retention=1000` automatically `Compact` on `"latest revision" - 1000` every 5-minute (when latest revision is 30000, compact on revision 29000). For instance, `--auto-compaction-mode=periodic --auto-compaction-retention=72h` automatically `Compact` with 72-hour retention windown, for every 7.2-hour. For instance, `--auto-compaction-mode=periodic --auto-compaction-retention=30m` automatically `Compact` with 30-minute retention windown, for every 3-minute. Periodic compactor continues to record latest revisions for every 1/10 of given compaction period (e.g. 1-hour when `--auto-compaction-mode=periodic --auto-compaction-retention=10h`). For every 1/10 of given compaction period, compactor uses the last revision that was fetched before compaction period, to discard historical data. The retention window of compaction period moves for every 1/10 of given compaction period. For instance, when hourly writes are 100 and `--auto-compaction-retention=10`, v3.1 compacts revision 1000, 2000, and 3000 for every 10-hour, while v3.2.x, v3.3.0, v3.3.1, and v3.3.2 compact revision 1000, 1100, and 1200 for every 1-hour. Furthermore, when writes per minute are 1000, v3.3.0, v3.3.1, and v3.3.2 with `--auto-compaction-mode=periodic --auto-compaction-retention=30m` compact revision 30000, 33000, and 36000, for every 3-minute with more finer granularity.
 
 When `--auto-compaction-retention=10h`, etcd first waits 10-hour for the first compaction, and then does compaction every hour (1/10 of 10-hour) afterwards like this:
 
@@ -70,7 +70,7 @@ When `--auto-compaction-retention=10h`, etcd first waits 10-hour for the first c
 
 Whether compaction succeeds or not, this process repeats for every 1/10 of given compaction period. If compaction succeeds, it just removes compacted revision from historical revision records.
 
-In [v3.3.3](http://github.com/etcd-io/etcd/blob/master/CHANGELOG-3.3.md), `--auto-compaction-mode=revision --auto-compaction-retention=1000` automatically `Compact` on `"latest revision" - 1000` every 5-minute (when latest revision is 30000, compact on revision 29000). Previously, `--auto-compaction-mode=periodic --auto-compaction-retention=72h` automatically `Compact` with 72-hour retention windown for every 7.2-hour.  **Now, `Compact` happens, for every 1-hour but still with 72-hour retention window.** Previously, `--auto-compaction-mode=periodic --auto-compaction-retention=30m` automatically `Compact` with 30-minute retention windown for every 3-minute. **Now, `Compact` happens, for every 30-minute but still with 30-minute retention window.** Periodic compactor keeps recording latest revisions for every compaction period when given period is less than 1-hour, or for every 1-hour when given compaction period is greater than 1-hour (e.g. 1-hour when `--auto-compaction-mode=periodic --auto-compaction-retention=24h`). For every compaction period or 1-hour, compactor uses the last revision that was fetched before compaction period, to discard historical data. The retention window of compaction period moves for every given compaction period or hour. For instance, when hourly writes are 100 and `--auto-compaction-mode=periodic --auto-compaction-retention=24h`, `v3.2.x`, `v3.3.0`, `v3.3.1`, and `v3.3.2` compact revision 2400, 2640, and 2880 for every 2.4-hour, while `v3.3.3` *or later* compacts revision 2400, 2500, 2600 for every 1-hour. Furthermore, when `--auto-compaction-mode=periodic --auto-compaction-retention=30m` and writes per minute are about 1000, `v3.3.0`, `v3.3.1`, and `v3.3.2` compact revision 30000, 33000, and 36000, for every 3-minute, while `v3.3.3` *or later* compacts revision 30000, 60000, and 90000, for every 30-minute.
+In [v3.3.3](http://github.com/etcd-io/etcd/blob/main/CHANGELOG-3.3.md), `--auto-compaction-mode=revision --auto-compaction-retention=1000` automatically `Compact` on `"latest revision" - 1000` every 5-minute (when latest revision is 30000, compact on revision 29000). Previously, `--auto-compaction-mode=periodic --auto-compaction-retention=72h` automatically `Compact` with 72-hour retention windown for every 7.2-hour.  **Now, `Compact` happens, for every 1-hour but still with 72-hour retention window.** Previously, `--auto-compaction-mode=periodic --auto-compaction-retention=30m` automatically `Compact` with 30-minute retention windown for every 3-minute. **Now, `Compact` happens, for every 30-minute but still with 30-minute retention window.** Periodic compactor keeps recording latest revisions for every compaction period when given period is less than 1-hour, or for every 1-hour when given compaction period is greater than 1-hour (e.g. 1-hour when `--auto-compaction-mode=periodic --auto-compaction-retention=24h`). For every compaction period or 1-hour, compactor uses the last revision that was fetched before compaction period, to discard historical data. The retention window of compaction period moves for every given compaction period or hour. For instance, when hourly writes are 100 and `--auto-compaction-mode=periodic --auto-compaction-retention=24h`, `v3.2.x`, `v3.3.0`, `v3.3.1`, and `v3.3.2` compact revision 2400, 2640, and 2880 for every 2.4-hour, while `v3.3.3` *or later* compacts revision 2400, 2500, 2600 for every 1-hour. Furthermore, when `--auto-compaction-mode=periodic --auto-compaction-retention=30m` and writes per minute are about 1000, `v3.3.0`, `v3.3.1`, and `v3.3.2` compact revision 30000, 33000, and 36000, for every 3-minute, while `v3.3.3` *or later* compacts revision 30000, 60000, and 90000, for every 30-minute.
 
 ## Defragmentation