From be458a7987b695a2cc7e9496bef1728a78aeadd4 Mon Sep 17 00:00:00 2001
From: Karl Nilsson <kjnilsson@gmail.com>
Date: Wed, 27 Nov 2024 13:56:55 +0000
Subject: [PATCH] Handle case where mem table is deleted during segment writer
 flush

---
 src/ra_log_segment_writer.erl | 24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/src/ra_log_segment_writer.erl b/src/ra_log_segment_writer.erl
index 1e618bc3..87be5737 100644
--- a/src/ra_log_segment_writer.erl
+++ b/src/ra_log_segment_writer.erl
@@ -360,16 +360,6 @@ send_segments(System, ServerUId, TidRanges, SegRefs) ->
             ok
     end.
 
-clean_closed_mem_tables(System, UId, Tid) ->
-    {ok, ClosedTbl} = ra_system:lookup_name(System, closed_mem_tbls),
-    Tables = ets:lookup(ClosedTbl, UId),
-    [begin
-         ?DEBUG("~w: cleaning closed table for '~ts' range: ~b-~b",
-                [?MODULE, UId, From, To]),
-         %% delete the entry in the closed table lookup
-         true = ets:delete_object(ClosedTbl, O)
-     end || {_, _, From, To, T} = O <- Tables, T == Tid].
-
 append_to_segment(UId, Tid, StartIdx0, EndIdx, Seg, State) ->
     StartIdx = start_index(UId, StartIdx0),
     % EndIdx + 1 because FP
@@ -379,7 +369,7 @@ append_to_segment(_, _, StartIdx, EndIdx, Seg, Closed, _State)
   when StartIdx >= EndIdx ->
     {Seg, Closed};
 append_to_segment(UId, Tid, Idx, EndIdx, Seg0, Closed, State) ->
-    case ets:lookup(Tid, Idx) of
+    try ets:lookup(Tid, Idx) of
         [] ->
             StartIdx = start_index(UId, Idx),
             case Idx < StartIdx of
@@ -422,8 +412,6 @@ append_to_segment(UId, Tid, Idx, EndIdx, Seg0, Closed, State) ->
                         undefined ->
                             %% a successor cannot be opened - this is most likely due
                             %% to the directory having been deleted.
-                            %% clear close mem tables here
-                            _ = clean_closed_mem_tables(State#state.system, UId, Tid),
                             undefined;
                         Seg ->
                             ok = counters:add(State#state.counter, ?C_SEGMENTS, 1),
@@ -437,6 +425,16 @@ append_to_segment(UId, Tid, Idx, EndIdx, Seg0, Closed, State) ->
                     FileName = ra_log_segment:filename(Seg0),
                     exit({segment_writer_append_error, FileName, Posix})
             end
+    catch _:badarg ->
+              ?ERROR("segment_writer: uid ~s ets table deleted", [UId]),
+              %% ets table has been deleted.
+              %% this could be due to two reasons
+              %% 1. the ra server has been deleted.
+              %% 2. an old mem table has been deleted due to snapshotting
+              %% but the member is still active
+              %% skipping this table
+              undefined
+
     end.
 
 find_segment_files(Dir) ->