diff --git a/packages/backend-rs/src/database/postgresql.rs b/packages/backend-rs/src/database/postgresql.rs
index 03b610598d..212183cbf2 100644
--- a/packages/backend-rs/src/database/postgresql.rs
+++ b/packages/backend-rs/src/database/postgresql.rs
@@ -16,6 +16,9 @@ async fn init_database() -> Result<&'static DbConn, DbErr> {
     let option: ConnectOptions = ConnectOptions::new(database_uri)
         .sqlx_logging_level(LevelFilter::Trace)
         .to_owned();
+
+    tracing::info!("Initializing PostgreSQL connection");
+
     let conn = Database::connect(option).await?;
     Ok(DB_CONN.get_or_init(move || conn))
 }
diff --git a/packages/backend-rs/src/database/redis.rs b/packages/backend-rs/src/database/redis.rs
index f8f6c712de..fe5d3bb5d5 100644
--- a/packages/backend-rs/src/database/redis.rs
+++ b/packages/backend-rs/src/database/redis.rs
@@ -26,6 +26,8 @@ fn init_redis() -> Result<Client, RedisError> {
         params.concat()
     };
 
+    tracing::info!("Initializing Redis connection");
+
     Client::open(redis_url)
 }
 
diff --git a/packages/backend-rs/src/misc/check_word_mute.rs b/packages/backend-rs/src/misc/check_word_mute.rs
index 18b550c29b..cee262c35a 100644
--- a/packages/backend-rs/src/misc/check_word_mute.rs
+++ b/packages/backend-rs/src/misc/check_word_mute.rs
@@ -39,7 +39,7 @@ async fn all_texts(note: NoteLike) -> Result<Vec<String>, DbErr> {
             .flatten(),
     );
 
-    if let Some(renote_id) = note.renote_id {
+    if let Some(renote_id) = &note.renote_id {
         if let Some((text, cw)) = note::Entity::find_by_id(renote_id)
             .select_only()
             .columns([note::Column::Text, note::Column::Cw])
@@ -53,10 +53,12 @@ async fn all_texts(note: NoteLike) -> Result<Vec<String>, DbErr> {
             if let Some(c) = cw {
                 texts.push(c);
             }
+        } else {
+            tracing::warn!("nonexistent renote id: {:#?}", renote_id);
         }
     }
 
-    if let Some(reply_id) = note.reply_id {
+    if let Some(reply_id) = &note.reply_id {
         if let Some((text, cw)) = note::Entity::find_by_id(reply_id)
             .select_only()
             .columns([note::Column::Text, note::Column::Cw])
@@ -70,6 +72,8 @@ async fn all_texts(note: NoteLike) -> Result<Vec<String>, DbErr> {
             if let Some(c) = cw {
                 texts.push(c);
             }
+        } else {
+            tracing::warn!("nonexistent reply id: {:#?}", reply_id);
         }
     }
 
diff --git a/packages/backend-rs/src/misc/reaction.rs b/packages/backend-rs/src/misc/reaction.rs
index a29ddf95de..f0afe345da 100644
--- a/packages/backend-rs/src/misc/reaction.rs
+++ b/packages/backend-rs/src/misc/reaction.rs
@@ -97,6 +97,8 @@ pub async fn to_db_reaction(reaction: Option<&str>, host: Option<&str>) -> Resul
                 {
                     return Ok(format!(":{name}@{ascii_host}:"));
                 }
+
+                tracing::info!("nonexistent remote custom emoji: :{name}@{ascii_host}:");
             } else {
                 // local emoji
                 // TODO: Does SeaORM have the `exists` method?
@@ -109,6 +111,8 @@ pub async fn to_db_reaction(reaction: Option<&str>, host: Option<&str>) -> Resul
                 {
                     return Ok(format!(":{name}:"));
                 }
+
+                tracing::info!("nonexistent local custom emoji: :{name}:");
             }
         };
     };
diff --git a/packages/backend-rs/src/misc/remove_old_attestation_challenges.rs b/packages/backend-rs/src/misc/remove_old_attestation_challenges.rs
index c5c3e0a2af..a70b784bae 100644
--- a/packages/backend-rs/src/misc/remove_old_attestation_challenges.rs
+++ b/packages/backend-rs/src/misc/remove_old_attestation_challenges.rs
@@ -8,10 +8,12 @@ use sea_orm::{ColumnTrait, DbErr, EntityTrait, QueryFilter};
 /// Delete all entries in the "attestation_challenge" table created at more than 5 minutes ago
 #[crate::export]
 pub async fn remove_old_attestation_challenges() -> Result<(), DbErr> {
-    attestation_challenge::Entity::delete_many()
+    let res = attestation_challenge::Entity::delete_many()
         .filter(attestation_challenge::Column::CreatedAt.lt(Local::now() - Duration::minutes(5)))
         .exec(db_conn().await?)
         .await?;
 
+    tracing::info!("{} attestation challenges are removed", res.rows_affected);
+
     Ok(())
 }