Prepare changelog for Release v0.34.20 (#9032)

CHANGELOG.md

@@ -2,21 +2,20 @@
 
 Friendly reminder, we have a [bug bounty program](https://hackerone.com/cosmos).
 
-## v0.34.20-rc1
+## v0.34.20
 
 Special thanks to external contributors on this release: @joeabbey @yihuang
 
+This release introduces a prioritized mempool. Further notes can be found in UPGRADING.md.
+
+NOTE: There's a known issue when combining the prioritized mempool with the ABCI socket client, that the team are curently working to resolve. Read more about the issue [here](https://github.com/tendermint/tendermint/pull/9030).
+
 ### BUG FIXES
 
+- [blocksync] [\#8496](https://github.com/tendermint/tendermint/pull/8496) validate block against state before persisting it to disk (@cmwaters)
 - [indexer] [#8625](https://github.com/tendermint/tendermint/pull/8625) Fix overriding tx index of duplicated txs. (@yihuang)
 - [mempool] [\#8962](https://github.com/tendermint/tendermint/issues/8962) Backport priority mempool fixes from v0.35.x to v0.34.x (@creachadair).
 
-## v0.34.20-rc0
-
-This RC introduces the prioritized mempool.
-
-NOTE: There's a known memory leak with the prioritized mempool that the team are currently working on resolving. We will cut v0.34.20 when this has been resolved. This release candidate is to provide the SDK with the new APIs. Read more about the issue [here](https://github.com/tendermint/tendermint/issues/8775)
-
 ### FEATURES
 
 - [cli] [\#8674] Add command to force compact goleveldb databases (@cmwaters)
@@ -26,10 +25,6 @@ NOTE: There's a known memory leak with the prioritized mempool that the team are
 
 - [logging] [\#8845](https://github.com/tendermint/tendermint/issues/8845) Add "Lazy" Stringers to defer Sprintf and Hash until logs print. (@joeabbey)
 
-### BUG FIXES
-
-- [blocksync] [\#8496](https://github.com/tendermint/tendermint/pull/8496) validate block against state before persisting it to disk (@cmwaters)
-
 ## v0.34.19
 
 ### BUG FIXES

CHANGELOG_PENDING.md

@@ -1,6 +1,6 @@
 # Unreleased Changes
 
-## v0.34.20
+## v0.34.21
 
 Special thanks to external contributors on this release:
 

UPGRADING.md

@@ -2,13 +2,28 @@
 
 This guide provides instructions for upgrading to specific versions of Tendermint Core.
 
+## v0.34.20
+
+### Feature: Priority Mempool
+
+This release backports an implementation of the Priority Mempool from the v0.35
+branch. This implementation of the mempool permits the application to set a
+priority on each transaction during CheckTx, and during block selection the
+highest-priority transactions are chosen (subject to the constraints on size
+and gas cost).
+
+Operators can enable the priority mempool by setting `mempool.version` to
+`"v1"` in the `config.toml`. For more technical details about the priority
+mempool, see [ADR 067: Mempool
+Refactor](https://github.com/tendermint/tendermint/blob/master/docs/architecture/adr-067-mempool-refactor.md).
+
 ## v0.34.0
 
 **Upgrading to Tendermint 0.34 requires a blockchain restart.**
 This release is not compatible with previous blockchains due to changes to
 the encoding format (see "Protocol Buffers," below) and the block header (see "Blockchain Protocol").
 
-Note also that Tendermint 0.34 also requires Go 1.15 or higher. 
+Note also that Tendermint 0.34 also requires Go 1.15 or higher.
 
 ### ABCI Changes
 
@@ -112,7 +127,7 @@ Tendermint 0.34 includes new and updated consensus parameters.
 
 #### Evidence Parameters
 
-* `MaxBytes`, which caps the total amount of evidence. The default is 1048576 (1 MB). 
+* `MaxBytes`, which caps the total amount of evidence. The default is 1048576 (1 MB).
 
 ### Crypto
 
@@ -188,15 +203,15 @@ blockchains, we recommend that you check the chain ID.
 
 ### Version
 
-Version is now set through Go linker flags `ld_flags`. Applications that are using tendermint as a library should set this at compile time. 
+Version is now set through Go linker flags `ld_flags`. Applications that are using tendermint as a library should set this at compile time.
 
 Example:
 
 ```sh
 go install -mod=readonly -ldflags "-X github.com/tendermint/tendermint/version.TMCoreSemVer=$(go list -m github.com/tendermint/tendermint | sed  's/ /\@/g') -s -w " -trimpath ./cmd
 ```
 
-Additionally, the exported constant `version.Version` is now `version.TMCoreSemVer`. 
+Additionally, the exported constant `version.Version` is now `version.TMCoreSemVer`.
 
 ## v0.33.4