clarify insert/race condition error message (#40)

* clarify insert/race condition error message

* clarify node message

gantry/clients/db/insert.py

@@ -52,7 +52,10 @@ async def insert_node(db: aiosqlite.Connection, node: dict) -> int:
     pk = await get_node(db, node["uuid"])
 
     if pk is None:
-        logger.error(f"node not inserted: {node}. data is likely missing")
+        logger.error(
+            f"node not inserted: {node}. either a duplicate insert was attempted,\
+            or the insert failed due to missing data"
+        )
 
     return pk
 
@@ -66,11 +69,15 @@ async def insert_job(db: aiosqlite.Connection, job: dict) -> int:
             job,
             # if the job somehow gets added into the db (pod+id being unique)
             # then ignore the insert
+            # in this case, lastrowid will be 0
             ignore=True,
         )
     ) as cursor:
         if cursor.rowcount > 0:
             return cursor.lastrowid
 
-    logger.error(f"job not inserted: {job}. data is likely missing")
+    logger.error(
+        f"job not inserted: {job}. either a duplicate insert was attempted,\
+        or the insert failed due to missing data"
+    )
     return None