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Simplify the Z0DAN add_node process. #286

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Simplify the Z0DAN add_node process. #286

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33 changes: 13 additions & 20 deletions samples/Z0DAN/zodan.sql
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Original file line number Diff line number Diff line change
Expand Up @@ -2142,7 +2142,7 @@ CREATE OR REPLACE PROCEDURE spock.check_commit_timestamp_and_advance_slot(
) LANGUAGE plpgsql AS $$
DECLARE
rec RECORD;
commit_ts timestamp;
start_point record;
slot_name text;
dbname text;
remotesql text;
Expand All @@ -2159,16 +2159,18 @@ BEGIN
FOR rec IN SELECT * FROM temp_spock_nodes WHERE node_name != src_node_name AND node_name != new_node_name LOOP
-- Check commit timestamp for lag from "other" node to new node
BEGIN
remotesql := format('SELECT commit_timestamp FROM spock.lag_tracker WHERE origin_name = %L AND receiver_name = %L',
rec.node_name, new_node_name);
remotesql := format('SELECT commit_lsn, commit_timestamp
FROM spock.lag_tracker
WHERE origin_name = %L AND receiver_name = %L',
rec.node_name, new_node_name);
IF verb THEN
RAISE NOTICE ' Remote SQL for commit timestamp check: %', remotesql;
END IF;

SELECT * FROM dblink(new_node_dsn, remotesql) AS t(ts timestamp) INTO commit_ts;
SELECT * FROM dblink(new_node_dsn, remotesql) AS t(lsn pg_lsn, ts timestamp) INTO start_point;

IF commit_ts IS NOT NULL THEN
RAISE NOTICE ' OK: %', rpad('Found commit timestamp for ' || rec.node_name || '->' || new_node_name || ': ' || commit_ts, 120, ' ');
IF start_point.ts IS NOT NULL THEN
RAISE NOTICE ' OK: %', rpad('Found commit timestamp for ' || rec.node_name || '->' || new_node_name || ': ' || start_point.ts, 120, ' ');
ELSE
RAISE NOTICE ' - %', rpad('No commit timestamp found for ' || rec.node_name || '->' || new_node_name, 120, ' ');
CONTINUE;
Expand Down Expand Up @@ -2205,7 +2207,6 @@ BEGIN

DECLARE
current_lsn pg_lsn;
target_lsn pg_lsn;
BEGIN
SELECT * FROM dblink(rec.dsn, remotesql) AS t(lsn pg_lsn) INTO current_lsn;

Expand All @@ -2214,31 +2215,23 @@ BEGIN
CONTINUE;
END IF;

-- Get target LSN from commit timestamp
remotesql := format('SELECT spock.get_lsn_from_commit_ts(%L, %L::timestamp)', slot_name, commit_ts);
IF verb THEN
RAISE NOTICE ' Remote SQL for LSN lookup: %', remotesql;
END IF;

SELECT * FROM dblink(rec.dsn, remotesql) AS t(lsn pg_lsn) INTO target_lsn;

IF target_lsn IS NULL OR target_lsn <= current_lsn THEN
RAISE NOTICE ' - Slot % already at or beyond target LSN (current: %, target: %)', slot_name, current_lsn, target_lsn;
IF start_point.lsn IS NULL OR start_point.lsn <= current_lsn THEN
RAISE NOTICE ' - Slot % already at or beyond target LSN (current: %, target: %)', slot_name, current_lsn, start_point.lsn;
CONTINUE;
END IF;

-- Advance the slot
remotesql := format('SELECT pg_replication_slot_advance(%L, %L::pg_lsn)', slot_name, target_lsn);
remotesql := format('SELECT pg_replication_slot_advance(%L, %L::pg_lsn)', slot_name, start_point.lsn);
IF verb THEN
RAISE NOTICE ' Remote SQL for slot advancement: %', remotesql;
END IF;

PERFORM * FROM dblink(rec.dsn, remotesql) AS t(result text);
RAISE NOTICE ' OK: %', rpad('Advanced slot ' || slot_name || ' from ' || current_lsn || ' to ' || target_lsn, 120, ' ');
RAISE NOTICE ' OK: %', rpad('Advanced slot ' || slot_name || ' from ' || current_lsn || ' to ' || start_point.lsn, 120, ' ');
END;
EXCEPTION
WHEN OTHERS THEN
RAISE NOTICE ' ✗ %', rpad('Advancing slot ' || slot_name || ' to timestamp ' || commit_ts || ' (error: ' || SQLERRM || ')', 120, ' ');
RAISE NOTICE ' ✗ %', rpad('Advancing slot ' || slot_name || ' to timestamp ' || start_point.ts || ' (error: ' || SQLERRM || ')', 120, ' ');
-- Continue with other nodes even if this one fails
END;
END LOOP;
Expand Down