v5.0.6 (#907)

* changelog

* text

ol/changelog/5_0_6.md

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+## 5.0.6
+
+This is an upgrade with patches mitigate an ongoing network incident. More details here: https://hackmd.io/KY7VklgAR72Bg7ETTQZAxA
+
+These changes do not affect Move code (no changes to system state or policies). It only upgrades `diem-node`
+
+#### TL;DR
+
+Just update binaries to use patches.
+
+```
+
+# install new binaries
+cd ~/libra
+git checkout v5.0.6 -f
+make bins install
+<stop diem-node>
+<restart diem-node>
+
+```
+
+### Summary
+
+TBD
+
+### Changes
+
+##### Move Changes
+None
+
+##### Rust Changes
+##### - prevent DiemAccount::1003 txs from remaining in mempool
+
+One line change to prevent the VM transaction verification on admission from allowing transactions from clients that are more advanced than the current state of validator. The change prevents a DiemAccount::1003 PROLOGUE_ESEQUENCE_NUMBER_TOO_NEW transaction error from remaining in the mempool.
+
+This happens when a TX has a sequence number newer than the validator has for that account. This means the validator is behind sync compared to the client.
+
+Possible fix to inundation of prologue errors DiemAccount::1003 during the Dec 16-18 network incident described here https://hackmd.io/KY7VklgAR72Bg7ETTQZAxA.
+
+It seems txs with prologue errors keep accumulating but they in mempool and then keep getting rebroadcast to other nodes that were disconnected (related PR: diem/diem#9437). This seems to contribute network to halt. But it's still unclear why this would cause transport errors, and eventually Validators from contacting each other. cc @gregnazario
+
+Tip from user shb
+https://discord.com/channels/903339070925721652/916100220855648296/921932021884928030
+"One idea for a mitigation: try setting this flag to false (which should tell mempool to drop any txs with new sequence #'s on the floor instead of holding on to them) https://github.com/OLSF/libra/blob/main/language/diem-vm/src/diem_transaction_validator.rs#L91
+
+https://github.com/OLSF/libra/pull/906
+
+##### - disable mempool resends all txns after disconnect
+
+Validators don't resend txns after disconnect to ones that have already
+confirmed which could cause some issues when many nodes restart or get
+stuck.
+
+This patch already exists in diem Upstream in a newer version (1.4) than 0L's fork (1.3). The upstream PR is https://github.com/diem/diem/pull/9437
+
+https://github.com/OLSF/libra/pull/905
+
+
+##### Tests
+
+- All continuous integration tests passed.
+- The diem-code was tested on production nodes that were both synced and out of sync.
+
+##### Compatibility
+The Move framework changes are backwards compatible with `diem-node` from v5.0.1
+
+### Rust changes
+#### Diem Node
+Changes to `diem-node` is compatible with on-chain state from `v5.0.5`.