feat(duplication): improve dups command to make the output info eas…

…ier to understand (apache#2167)

Improvements for the command of listing duplications have been made in
the following aspects:

- change the description for the stats of duplication by status and follower
cluster to avoid misunderstanding.
- add `DS_LOG` as the prerequisite for a duplication to be considered as
finished.
- introduce a new partition-level column showing the gap between confirmed
decree and last committed decree.
- fix the options for json format and output file.

src/shell/commands/duplication.cpp

@@ -135,12 +135,13 @@ void attach_dups_stat(const list_dups_stat &stat, dsn::utils::multi_table_printe
     printer.add_row_name_and_data("unfinished_app_count", stat.unfinished_app_count);
 
     // Add stats for duplications.
-    printer.add_row_name_and_data("duplication_count", stat.duplication_count);
+    printer.add_row_name_and_data("total_duplication_count", stat.duplication_count);
     for (const auto &[status, cnt] : stat.dup_status_stats) {
-        printer.add_row_name_and_data(fmt::format("{}_count", status), cnt);
+        printer.add_row_name_and_data(fmt::format("duplication_count_by_status({})", status), cnt);
     }
     for (const auto &[remote_cluster, cnt] : stat.dup_remote_cluster_stats) {
-        printer.add_row_name_and_data(fmt::format("{}_count", remote_cluster), cnt);
+        printer.add_row_name_and_data(
+            fmt::format("duplication_count_by_follower_cluster({})", remote_cluster), cnt);
     }
 
     // Add stats for partitions.
@@ -191,15 +192,18 @@ void stat_dups(const ls_app_dups_map &app_states, uint32_t progress_gap, list_du
             }
 
             for (const auto &[partition_id, partition_state] : dup.partition_states) {
-                if (partition_state.last_committed_decree < partition_state.confirmed_decree) {
-                    // This is unlikely to happen.
-                    continue;
-                }
-
-                if (partition_state.last_committed_decree - partition_state.confirmed_decree <=
-                    progress_gap) {
-                    // This partition is defined as "finished".
-                    continue;
+                // Only in the status of `DS_LOG`could a duplication be considered as "finished".
+                if (dup.status == duplication_status::DS_LOG) {
+                    if (partition_state.last_committed_decree < partition_state.confirmed_decree) {
+                        // This is unlikely to happen.
+                        continue;
+                    }
+
+                    if (partition_state.last_committed_decree - partition_state.confirmed_decree <=
+                        progress_gap) {
+                        // This partition is defined as "finished".
+                        continue;
+                    }
                 }
 
                 // Just assign with 1 to dedup, in case calculated multiple times.
@@ -231,14 +235,15 @@ void add_titles_for_dups(bool list_partitions, dsn::utils::table_printer &printe
     printer.add_column("dup_id", tp_alignment::kRight);
     printer.add_column("create_time", tp_alignment::kRight);
     printer.add_column("status", tp_alignment::kRight);
-    printer.add_column("remote_cluster", tp_alignment::kRight);
-    printer.add_column("remote_app_name", tp_alignment::kRight);
+    printer.add_column("follower_cluster", tp_alignment::kRight);
+    printer.add_column("follower_app_name", tp_alignment::kRight);
 
     if (list_partitions) {
         // Partition-level info.
         printer.add_column("partition_id", tp_alignment::kRight);
         printer.add_column("confirmed_decree", tp_alignment::kRight);
         printer.add_column("last_committed_decree", tp_alignment::kRight);
+        printer.add_column("decree_gap", tp_alignment::kRight);
     }
 }
 
@@ -300,6 +305,8 @@ void add_row_for_dups(int32_t app_id,
         printer.append_data(partition_id);
         printer.append_data(partition_state.confirmed_decree);
         printer.append_data(partition_state.last_committed_decree);
+        printer.append_data(partition_state.last_committed_decree -
+                            partition_state.confirmed_decree);
     }
 }
 
@@ -631,8 +638,9 @@ bool ls_dups(command_executor *e, shell_context *sc, arguments args)
 
     // All valid parameters and flags are given as follows.
     static const std::set<std::string> params = {
-        "a", "app_name_pattern", "m", "match_type", "g", "progress_gap"};
-    static const std::set<std::string> flags = {"p", "list_partitions", "u", "show_unfinishd"};
+        "a", "app_name_pattern", "m", "match_type", "g", "progress_gap", "o", "output"};
+    static const std::set<std::string> flags = {
+        "p", "list_partitions", "u", "show_unfinishd", "j", "json"};
 
     argh::parser cmd(args.argc, args.argv, argh::parser::PREFER_PARAM_FOR_UNREG_OPTION);