# Known Issues — 2025.1 (Epoxy)

### Partial upgrade with `--limit` corrupts cluster state

**Symptom:** After running `kolla-ansible upgrade --limit <host>`, services on non-limited hosts fail to communicate with upgraded hosts. API errors, RPC timeouts, and DB schema mismatches appear across the cluster.

**Cause:** OpenStack upgrades involve DB schema migrations and RPC version negotiations. Running upgrade on a subset of hosts leaves the cluster in a split-version state where migrated schemas and RPC versions are incompatible with non-upgraded services.

**Workaround:** Never use `--limit` with `kolla-ansible upgrade`. Always upgrade the entire cluster in one operation. If you've already done a partial upgrade, complete the upgrade on all remaining hosts immediately.

**Affected versions:** All kolla-ansible versions
**Status:** By design — not a bug, but a known operational constraint

---

### MariaDB Galera cluster fails to bootstrap after power loss

**Symptom:** After a full power loss (all controllers down simultaneously), MariaDB containers fail to start. Logs show `WSREP: failed to open channel` and the galera cluster cannot form.

**Cause:** No node has `safe_to_bootstrap: 1` in its grastate.dat because all nodes were shut down uncleanly.

**Workaround:**
1. On each controller, check `/var/lib/docker/volumes/mariadb/_data/grastate.dat`
2. Find the node with the highest `seqno` value
3. On that node, set `safe_to_bootstrap: 1` in grastate.dat
4. Run `kolla-ansible mariadb-recovery`

**Affected versions:** All kolla-ansible versions with MariaDB Galera
**Status:** Open — inherent to Galera's crash recovery design

---

### RabbitMQ cluster partition after network split

**Symptom:** After a network partition between controllers, RabbitMQ enters a split-brain state. OpenStack services log `ConnectionResetError` or `AMQP connection lost` repeatedly. Some services work, others don't depending on which RabbitMQ node they're connected to.

**Cause:** RabbitMQ's partition handling policy. Kolla-ansible defaults to `pause_minority` which stops the minority side, but if the partition is symmetric (2-node cluster) or transient, recovery may not be automatic.

**Workaround:**
1. Identify the partition: `docker exec rabbitmq rabbitmqctl cluster_status`
2. If partitioned: restart RabbitMQ on the minority nodes: `docker restart rabbitmq` on the affected hosts
3. If that fails: stop RabbitMQ on all nodes, then start them one at a time starting with the node that has the most recent data
4. Run `kolla-ansible reconfigure -t rabbitmq` to ensure consistent state

**Affected versions:** All kolla-ansible versions
**Status:** Open — inherent to distributed messaging systems

---

### Nova live migration fails with "Unsafe migration" error

**Symptom:** `openstack server migrate --live` fails with `Migration pre-check error: Unsafe migration: Migration may not be safe` or similar libvirt errors about CPU model incompatibility.

**Cause:** Compute nodes have different CPU models or features. Libvirt refuses live migration when the destination CPU doesn't support all features the guest is using.

**Workaround:** Set a common CPU model in `config/nova.conf`:
```ini
[libvirt]
cpu_mode = custom
cpu_model = Cascadelake-Server  # or another model common to all compute nodes
```
Then run `kolla-ansible reconfigure -t nova`.

**Affected versions:** All versions, any heterogeneous compute environment
**Status:** Open — requires operator configuration

---

### Horizon session timeout causes 500 errors instead of redirect to login

**Symptom:** After session timeout, Horizon shows a 500 Internal Server Error instead of redirecting to the login page. Browser console shows Django middleware errors.

**Cause:** Memcached session backend loses the session data, and Horizon's error handling doesn't gracefully handle the missing session.

**Workaround:** Clear browser cookies and reload. To reduce frequency, increase session timeout in `config/horizon/local_settings`:
```python
SESSION_TIMEOUT = 86400  # 24 hours instead of default 1800
```
Then run `kolla-ansible reconfigure -t horizon`.

**Affected versions:** 2025.1.0
**Status:** Fixed in 2025.1.1