docs: reference WAL segement ref-counting ticket

Reference the WAL ref-counting ticket in the WAL rotation task.

ingester2/src/persist/handle.rs

@@ -119,7 +119,7 @@ use crate::{
 ///     crate::ingest_state::IngestStateError::PersistSaturated
 #[derive(Debug)]
 pub(crate) struct PersistHandle {
-    /// THe state/dependencies shared across all worker tasks.
+    /// The state/dependencies shared across all worker tasks.
     worker_state: Arc<SharedWorkerState>,
 
     /// Task handles for the worker tasks, aborted on drop of all

ingester2/src/wal/rotate_task.rs

@@ -68,6 +68,8 @@ pub(crate) async fn periodic_rotation<T, P>(
         // special code path between "hot partition persist" and "wal rotation
         // persist" - it all works the same way!
         //
+        //      https://github.com/influxdata/influxdb_iox/issues/6566
+        //
         // TODO: this properly as described above.
 
         tokio::time::sleep(Duration::from_secs(5)).await;