At some point we'd need to failover db1109 (row D) to db1104 (row B).
There are some reason to do so:
- PDUs on row D will eventually need to be replaced like it happened with row A and B (T226778)
- We currently have many masters on row D, being db1109 one of them.
- There is an schema change that is waiting for the master to be altered to be fully complete:
Read only is required, and the following wikis will not allow writes during this maintenance window: {T237120}
```
wikidatawiki
```
Date: To be defined
**Note: the day before the failover disable the following cronjob per T239238#5697067**:
```
# Puppet Name: wikidata-rebuildItemTerms
30 * * * * /usr/bin/timeout 3500s /usr/local/bin/mwscript extensions/Wikibase/repo/maintenance/rebuildItemTerms.php --wiki wikidatawiki --batch-size 150 --sleep 2 --from-id $(/bin/sed -n '/Rebuilding Q[[:digit:]]\+ till Q\([[:digit:]]\+\)/ { s//\1/; p; }' /var/log/wikidata/wikidata-rebuildItemTerms.log* | /usr/bin/sort -rn | /usr/bin/head -1) >> /var/log/wikidata/wikidata-rebuildItemTerms.log 2>&1
```