Shardmaster renamed to shardlord.

Author: arssher

bin/cancel_cmd.sh

@@ -1,3 +1,3 @@
 #!/bin/bash
 
-kill -SIGUSR1 `ps aux | grep 'postgres: bgworker: shardmaster' | grep -v 'grep' | awk '{print $2}'`
+kill -SIGUSR1 `ps aux | grep 'postgres: bgworker: shardlord' | grep -v 'grep' | awk '{print $2}'`

bin/common.sh

@@ -13,13 +13,13 @@ function start_nodes()
 	port="${worker_ports[i]}"
 	pg_ctl -o "-p $port" -D $datadir  -l $logfile start
     done
-    pg_ctl -o "-p $master_port" -D $master_datadir -l $logfile start
+    pg_ctl -o "-p $lord_port" -D $lord_datadir -l $logfile start
 }
 
 function stop_nodes()
 {
     echo "Stopping nodes"
-    for datadir in $master_datadir "${worker_datadirs[@]}"; do
+    for datadir in $lord_datadir "${worker_datadirs[@]}"; do
 	pg_ctl -D $datadir stop || true
     done
 }
@@ -32,5 +32,5 @@ function restart_nodes()
 	port="${worker_ports[i]}"
 	pg_ctl -o "-p $port" -D $datadir -l $logfile restart
     done
-    pg_ctl -o "-p $master_port" -D $master_datadir -l $logfile restart
+    pg_ctl -o "-p $lord_port" -D $lord_datadir -l $logfile restart
 }

bin/setup.sh.example

@@ -3,8 +3,8 @@ pathmanpath=~/postgres/pg_pathman
 install_pathman=false
 logfile=$HOME/tmp/tmp/tmp.log
 
-master_datadir=~/postgres/data1
-master_port=5432
+lord_datadir=~/postgres/data1
+lord_port=5432
 
 # declare -a worker_datadirs=()
 # declare -a worker_ports=()

bin/shardman_init.sh

@@ -16,21 +16,21 @@ make install
 > $logfile
 
 stop_nodes
-for datadir in $master_datadir "${worker_datadirs[@]}"; do
+for datadir in $lord_datadir "${worker_datadirs[@]}"; do
     rm -rf "$datadir"
     mkdir -p "$datadir"
     initdb -D "$datadir"
 done
 
-cat postgresql.conf.common.template >> ${master_datadir}/postgresql.conf
-cat postgresql.conf.lord.template >> ${master_datadir}/postgresql.conf
+cat postgresql.conf.common.template >> ${lord_datadir}/postgresql.conf
+cat postgresql.conf.lord.template >> ${lord_datadir}/postgresql.conf
 for worker_datadir in "${worker_datadirs[@]}"; do
     cat postgresql.conf.common.template >> ${worker_datadir}/postgresql.conf
     cat postgresql.conf.worker.template >> ${worker_datadir}/postgresql.conf
 done
 
 start_nodes
-for port in $master_port "${worker_ports[@]}"; do
+for port in $lord_port "${worker_ports[@]}"; do
     createdb -p $port `whoami`
     psql -p $port -c "create extension pg_shardman cascade;"
 done

bin/shardman_start.sh

@@ -8,20 +8,20 @@ cd "${script_dir}/.."
 > $logfile
 
 restart_nodes # make sure nodes run
-# first workers, then master
-for port in "${worker_ports[@]}" $master_port; do
+# first workers, then lord
+for port in "${worker_ports[@]}" $lord_port; do
     psql -p $port -c "drop extension if exists pg_shardman cascade;"
 done
 
 make clean
 make install
 
 restart_nodes
-for port in $master_port "${worker_ports[@]}"; do
+for port in $lord_port "${worker_ports[@]}"; do
     psql -p $port -c "create extension pg_shardman cascade;"
 done
 
-# to restart master bgw
+# to restart lord bgw
 restart_nodes
 
 run_demo

init.sql

@@ -36,16 +36,16 @@ CREATE TABLE cmd_log (
 	status cmd_status DEFAULT 'waiting' NOT NULL
 );
 
--- Notify shardman master bgw about new commands
-CREATE FUNCTION notify_shardmaster() RETURNS trigger AS $$
+-- Notify shardlord bgw about new commands
+CREATE FUNCTION notify_shardlord() RETURNS trigger AS $$
 BEGIN
 	NOTIFY shardman_cmd_log_update;
 	RETURN NULL;
 END
 $$ LANGUAGE plpgsql;
 CREATE TRIGGER cmd_log_inserts
 	AFTER INSERT ON cmd_log
-	FOR EACH STATEMENT EXECUTE PROCEDURE notify_shardmaster();
+	FOR EACH STATEMENT EXECUTE PROCEDURE notify_shardlord();
 
 -- probably better to keep opts in an array field, but working with arrays from
 -- libpq is not very handy
@@ -83,7 +83,7 @@ END
 $$ LANGUAGE plpgsql;
 
 -- Shard table with hash partitions. Params as in pathman, except for relation
--- (master doesn't know oid of the table)
+-- (lord doesn't know oid of the table)
 CREATE FUNCTION create_hash_partitions(
 	node_id int, relation text, expr text, partitions_count int,
 	rebalance bool DEFAULT true)
@@ -162,39 +162,39 @@ END $$ LANGUAGE plpgsql STRICT;
 
 -- Internal functions
 
--- Called on shardmaster bgw start. Add itself to nodes table, set id, create
+-- Called on shardlord bgw start. Add itself to nodes table, set id, create
 -- publication.
-CREATE FUNCTION master_boot() RETURNS void AS $$
+CREATE FUNCTION lord_boot() RETURNS void AS $$
 DECLARE
-	-- If we have never booted as a master before, we have a work to do
-	init_master bool DEFAULT false;
-	master_connstring text;
-	master_id int;
+	-- If we have never booted as a lord before, we have a work to do
+	init_lord bool DEFAULT false;
+	lord_connstring text;
+	lord_id int;
 BEGIN
-	raise INFO 'Booting master';
+	raise INFO 'Booting lord';
 	PERFORM shardman.create_meta_pub();
 
-	master_id := shardman.my_id();
-	IF master_id IS NULL THEN
-		SELECT pg_settings.setting into master_connstring from pg_settings
-			WHERE NAME = 'shardman.master_connstring';
+	lord_id := shardman.my_id();
+	IF lord_id IS NULL THEN
+		SELECT pg_settings.setting INTO lord_connstring FROM pg_settings
+			WHERE NAME = 'shardman.shardlord_connstring';
 		EXECUTE format(
 			'INSERT INTO @extschema@.nodes VALUES (DEFAULT, %L, NULL, false, true)
-			RETURNING id', master_connstring) INTO master_id;
-		PERFORM shardman.set_node_id(master_id);
-		init_master := true;
+			RETURNING id', lord_connstring) INTO lord_id;
+		PERFORM shardman.set_node_id(lord_id);
+		init_lord := true;
 	ELSE
-		EXECUTE 'SELECT NOT (SELECT master FROM shardman.nodes WHERE id = $1)'
-			INTO init_master USING master_id;
-		EXECUTE 'UPDATE shardman.nodes SET master = true WHERE id = $1' USING master_id;
+		EXECUTE 'SELECT NOT (SELECT lord FROM shardman.nodes WHERE id = $1)'
+			INTO init_lord USING lord_id;
+		EXECUTE 'UPDATE shardman.nodes SET lord = true WHERE id = $1' USING lord_id;
 	END IF;
-	IF init_master THEN
+	IF init_lord THEN
 		-- TODO: set up lr channels
 	END IF;
 END $$ LANGUAGE plpgsql;
 
 -- These tables will be replicated to worker nodes, notifying them about changes.
--- Called on master.
+-- Called on lord.
 CREATE FUNCTION create_meta_pub() RETURNS void AS $$
 BEGIN
 	IF NOT EXISTS (SELECT * FROM pg_publication WHERE pubname = 'shardman_meta_pub') THEN

membership.sql

@@ -15,16 +15,16 @@ CREATE TABLE nodes (
 	id serial PRIMARY KEY,
 	connstring text NOT NULL UNIQUE,
 	worker_status worker_node_status,
-	-- While currently we don't support master and worker roles on one node,
-	-- potentially node can be either worker, master or both, so we need 2 bits.
+	-- While currently we don't support lord and worker roles on one node,
+	-- potentially node can be either worker, lord or both, so we need 2 bits.
 	-- One bool with NULL might be fine, but it seems a bit counter-intuitive.
 	worker bool NOT NULL DEFAULT true,
-	master bool NOT NULL DEFAULT false,
+	lord bool NOT NULL DEFAULT false,
 	-- cmd by which node was added
 	added_by bigint REFERENCES shardman.cmd_log(id)
 );
 
--- Master is removing us, so reset our state, removing all subscriptions. A bit
+-- Lord is removing us, so reset our state, removing all subscriptions. A bit
 -- tricky part: we can't DROP SUBSCRIPTION here, because that would mean
 -- shooting (sending SIGTERM) ourselvers (to replication apply worker) in the
 -- leg.  So for now we just disable subscription, worker will stop after the end

postgresql.conf.lord.template

@@ -1,5 +1,5 @@
-shardman.master = on # this instance is shardlor?
-shardman.master_dbname = ars # lord's dbname
-shardman.master_connstring = 'port=5432' # lord's connstring
+shardman.shardlord = on # this instance is shardlord?
+shardman.shardlord_dbname = ars # shardlord's dbname
+shardman.shardlord_connstring = 'port=5432' # shardlord's connstring
 shardman.cmd_retry_naptime = 500 # sleep milliseconds after failure
 shardman.poll_interval = 500 # long operations poll frequency

readme.txt

@@ -1,15 +1,14 @@
 First, some terminology:
 'shardlord' or 'lord' is postgres instance and background process (bgw) spinning
-  on it which manages sharding. In some places it is still called 'shardmaster'
-  or 'master'.
+  on it which manages sharding.
 'worker nodes' or 'workers' are other nodes with data.
 'sharded table' is table managed by shardman.
 'shard' or 'partition' is any table containing part of sharded table.
 'primary' is main partition of sharded table, i.e. the only writable
   partition.
 'replica' is secondary partition of sharded table, i.e. read-only partition.
-'cluster' -- the whole system of shardlord and workers, or cluster in PostgreSQL
-  sense, this should be clear from the context.
+'cluster' -- either the whole system of shardlord and workers, or cluster in
+  traditional PostgreSQL sense, this should be clear from the context.
 
 For quick setup, see scripts in bin/ directory. Setup is configured in file
 setup.sh which needs to be placed in the same directory; see setup.sh.example

shard.sql

@@ -49,9 +49,9 @@ CREATE TRIGGER new_table_worker_side AFTER INSERT ON shardman.tables
 	FOR EACH ROW EXECUTE PROCEDURE new_table_worker_side();
 -- fire trigger only on worker nodes
 ALTER TABLE shardman.tables ENABLE REPLICA TRIGGER new_table_worker_side;
--- On master side, insert partitions.
+-- On lord side, insert partitions.
 -- All of them are primary and have no prev or nxt.
-CREATE FUNCTION new_table_master_side() RETURNS TRIGGER AS $$
+CREATE FUNCTION new_table_lord_side() RETURNS TRIGGER AS $$
 BEGIN
 	INSERT INTO shardman.partitions
 	SELECT part_name, NEW.initial_node AS owner, NULL, NULL, NEW.relation AS relation
@@ -61,8 +61,8 @@ BEGIN
 	RETURN NULL;
 END
 $$ LANGUAGE plpgsql;
-CREATE TRIGGER new_table_master_side AFTER INSERT ON shardman.tables
-	FOR EACH ROW EXECUTE PROCEDURE new_table_master_side();
+CREATE TRIGGER new_table_lord_side AFTER INSERT ON shardman.tables
+	FOR EACH ROW EXECUTE PROCEDURE new_table_lord_side();
 
 ------------------------------------------------------------
 -- Partitions

src/include/copypart.h

@@ -31,8 +31,7 @@ typedef enum
 } ExecTaskRes;
 
 /*
- *  Current step of 1 master partition move. See comments to corresponding
- *  funcs, e.g. start_tablesync.
+ *  Current step of 1 partition move.
  */
 typedef enum
 {

src/include/pg_shardman.h

@@ -22,9 +22,9 @@ extern volatile sig_atomic_t got_sigterm;
 extern volatile sig_atomic_t got_sigusr1;
 
 /* GUC variables */
-extern bool shardman_master;
-extern char *shardman_master_dbname;
-extern char *shardman_master_connstring;
+extern bool shardman_shardlord;
+extern char *shardman_shardlord_dbname;
+extern char *shardman_shardlord_connstring;
 extern int shardman_cmd_retry_naptime;
 extern int shardman_poll_interval;
 
@@ -52,7 +52,7 @@ typedef struct RepCount
 } RepCount;
 
 extern void _PG_init(void);
-extern void shardmaster_main(Datum main_arg);
+extern void shardlord_main(Datum main_arg);
 extern void check_for_sigterm(void);
 extern uint64 void_spi(char *sql);
 extern void update_cmd_status(int64 id, const char *new_status);