Downgrade from Database 8.0

This page describes how to downgrade from Database 8.0.

If you have no strong-consistency namespaces, you can downgrade from Database 8.0 without issue. If you have one or more strong-consistency namespaces, you must first verify that no transactions are ongoing.

caution

It is possible that some nodes may not know the state of prior transactions. If transactions have occurred, there may still be data in storage will be incompatible with older versions.

If you have used transactions or if you are unsure, use the following steps to downgrade:

Disable transaction writes:

asadm --enable -e "manage config namespace NAMESPACE param disable-mrt-writes to true"

Wait for the provisional count to reach zero on all nodes:
```
asadm -e "watch show stat like mrt_provisionals"
```
Wait for transaction monitor records in the monitor set to reach zero on all nodes:
```
asadm -e "show statistics sets for test <ERO~MRT like objects"
```
Do the following for each node, one node at a time:
1. Quiesce the node:
```
asadm --enable -e "manage quiesce with NODE-ID"
```
2. Stop the node:
```
sudo systemctl stop aerospike
```
3. Wipe storage to ensure that there isn't any incompatible data.
4. Downgrade the server package.
5. Start the node:
```
sudo systemctl start aerospike
```
6. Monitor the migration until complete:
```
asadm -e "watch show stat like migrate_partitions_remaining"
```