diff options
Diffstat (limited to 'contrib/replication')
| -rw-r--r-- | contrib/replication/README | 129 | ||||
| -rw-r--r-- | contrib/replication/configure-replication.sh | 186 |
2 files changed, 315 insertions, 0 deletions
diff --git a/contrib/replication/README b/contrib/replication/README new file mode 100644 index 00000000..4deb8a78 --- /dev/null +++ b/contrib/replication/README @@ -0,0 +1,129 @@ +README +------------ +$Id$ +Christopher Browne +cbbrowne@gmail.com +2006-09-29 +------------ + +The script configure-replication.sh is intended to allow the gentle user +to readily configure replication of the LedgerSMB database schema +using the Slony-I replication system for PostgreSQL. + +For more general details about Slony-I, see <http://slony.info/> + +This script uses a number of environment variables to determine the +shape of the configuration. In many cases, the defaults should be at +least nearly OK... + +Global: + CLUSTER - Name of Slony-I cluster + NUMNODES - Number of nodes to set up + + PGUSER - name of PostgreSQL superuser controlling replication + PGPORT - default port number + PGDATABASE - default database name + +For each node, there are also four parameters; for node 1: + DB1 - database to connect to + USER1 - superuser to connect as + PORT1 - port + HOST1 - host + +It is quite likely that DB*, USER*, and PORT* should be drawn from the +default PGDATABASE, PGUSER, and PGPORT values above; that sort of +uniformity is usually a good thing. + +In contrast, HOST* values should be set explicitly for HOST1, HOST2, +..., as you don't get much benefit from the redundancy replication +provides if all your databases are on the same server! + +slonik config files are generated in a temp directory under /tmp. The +usage is thus: + +1. preamble.slonik is a "preamble" containing connection info used by + the other scripts. + + Verify the info in this one closely; you may want to keep this + permanently to use with other maintenance you may want to do on the + cluster. + +2. create_set.slonik + + This is the first script to run; it sets up the requested nodes as + being Slony-I nodes, adding in some Slony-I-specific config tables + and such. + +You can/should start slon processes any time after this step has run. + +3. store_paths.slonik + + This is the second script to run; it indicates how the slons + should intercommunicate. It assumes that all slons can talk to + all nodes, which may not be a valid assumption in a + complexly-firewalled environment. + +4. create_set.slonik + + This sets up the replication set consisting of the whole bunch of + tables and sequences that make up the LedgerSMB database schema. + + When you run this script, all that happens is that triggers are + added on the origin node (node #1) that start collecting updates; + replication won't start until #5... + + There are two assumptions in this script that could be invalidated + by circumstances: + + 1. That all of the LedgerSMB tables and sequences have been + included. + + This becomes invalid if new tables get added to LedgerSMB and + don't get added to the TABLES list in the generator script. + + 2. That all tables have been defined with primary keys. + + This *should* be the case soon if not already. + +5. subscribe_set_2.slonik + + And 3, and 4, and 5, if you set the number of nodes higher... + + This is the step that "fires up" replication. + + The assumption that the script generator makes is that all the + subscriber nodes will want to subscribe directly to the origin + node. If you plan to have "sub-clusters", perhaps where there is + something of a "master" location at each data centre, you may + need to revise that. + + The slon processes really ought to be running by the time you + attempt running this step. To do otherwise would be rather + foolish. + +Once all of these slonik scripts have been run, replication may be +expected to continue to run as long as slons stay running. + +If you have an outage, where a database server or a server hosting +slon processes falls over, and it's not so serious that a database +gets mangled, then no big deal: Just restart the postmaster and +restart slon processes, and replication should pick up. + +If something does get mangled, then actions get more complicated: + +1 - If the failure was of the "origin" database, then you probably want + to use FAIL OVER to shift the "master" role to another system. + +2 - If a subscriber failed, and other nodes were drawing data from it, + then you could submit SUBSCRIBE SET requests to point those other + nodes to some node that is "less mangled." That is not a real big + deal; note that this does NOT require that they get re-subscribed + from scratch; they can pick up (hopefully) whatever data they + missed and simply catch up by using a different data source. + +Once you have reacted to the loss by reconfiguring the surviving nodes +to satisfy your needs, you may want to recreate the mangled node. See +the Slony-I Administrative Guide for more details on how to do that. +It is not overly profound; you need to drop out the mangled node, and +recreate it anew, which is not all that different from setting up +another subscriber. diff --git a/contrib/replication/configure-replication.sh b/contrib/replication/configure-replication.sh new file mode 100644 index 00000000..9edad3a9 --- /dev/null +++ b/contrib/replication/configure-replication.sh @@ -0,0 +1,186 @@ +#!/bin/bash +# $Id$ + +# Global defaults +CLUSTER=${CLUSTER:-"LedgerSMB"} +NUMNODES=${NUMNODES:-"2"} + +# Defaults - origin node +DB1=${DB1:-${PGDATABASE:-"ledgersmb"}} +HOST1=${HOST1:-`hostname`} +USER1=${USER1:-${PGUSER:-"slony"}} +PORT1=${PORT1:-${PGPORT:-"5432"}} + +# Defaults - node 2 +DB2=${DB2:-${PGDATABASE:-"ledgersmb"}} +HOST2=${HOST2:-"backup.example.info"} +USER2=${USER2:-${PGUSER:-"slony"}} +PORT2=${PORT2:-${PGPORT:-"5432"}} + +# Defaults - node 3 +DB3=${DB3:-${PGDATABASE:-"ledgersmb"}} +HOST3=${HOST3:-"backup3.example.info"} +USER3=${USER3:-${PGUSER:-"slony"}} +PORT3=${PORT3:-${PGPORT:-"5432"}} + +# Defaults - node 4 +DB4=${DB4:-${PGDATABASE:-"ledgersmb"}} +HOST4=${HOST4:-"backup4.example.info"} +USER4=${USER4:-${PGUSER:-"slony"}} +PORT4=${PORT4:-${PGPORT:-"5432"}} + +# Defaults - node 5 +DB5=${DB5:-${PGDATABASE:-"ledgersmb"}} +HOST5=${HOST5:-"backup5.example.info"} +USER5=${USER5:-${PGUSER:-"slony"}} +PORT5=${PORT5:-${PGPORT:-"5432"}} + +store_path() +{ + +echo "include <${PREAMBLE}>;" > $mktmp/store_paths.slonik + i=1 + while : ; do + eval db=\$DB${i} + eval host=\$HOST${i} + eval user=\$USER${i} + eval port=\$PORT${i} + + if [ -n "${db}" -a "${host}" -a "${user}" -a "${port}" ]; then + j=1 + while : ; do + if [ ${i} -ne ${j} ]; then + eval bdb=\$DB${j} + eval bhost=\$HOST${j} + eval buser=\$USER${j} + eval bport=\$PORT${j} + if [ -n "${bdb}" -a "${bhost}" -a "${buser}" -a "${bport}" ]; then + echo "STORE PATH (SERVER=${i}, CLIENT=${j}, CONNINFO='dbname=${db} host=${host} user=${user} port=${port}');" >> $mktmp/store_paths.slonik + else + err 3 "No conninfo" + fi + fi + if [ ${j} -ge ${NUMNODES} ]; then + break; + else + j=$((${j} + 1)) + fi + done + if [ ${i} -ge ${NUMNODES} ]; then + break; + else + i=$((${i} +1)) + fi + else + err 3 "no DB" + fi + done +} + +mktmp=`mktemp -d -t ledgersmb-temp.XXXXXX` +if [ $MY_MKTEMP_IS_DECREPIT ] ; then + mktmp=`mktemp -d /tmp/ledgersmb-temp.XXXXXX` +fi + +PREAMBLE=${mktmp}/preamble.slonik + +echo "cluster name=${CLUSTER};" > $PREAMBLE + +alias=1 + +while : ; do + eval db=\$DB${alias} + eval host=\$HOST${alias} + eval user=\$USER${alias} + eval port=\$PORT${alias} + + if [ -n "${db}" -a "${host}" -a "${user}" -a "${port}" ]; then + conninfo="dbname=${db} host=${host} user=${user} port=${port}" + echo "NODE ${alias} ADMIN CONNINFO = '${conninfo}';" >> $PREAMBLE + if [ ${alias} -ge ${NUMNODES} ]; then + break; + else + alias=`expr ${alias} + 1` + fi + else + break; + fi +done + + +SEQUENCES=" acc_trans_entry_id_seq audittrail_entry_id_seq + custom_field_catalog_field_id_seq custom_table_catalog_table_id_seq + id inventory_entry_id_seq invoiceid jcitemsid orderitemsid + partscustomer_entry_id_seq partsvendor_entry_id_seq + session_session_id_seq shipto_entry_id_seq " + +TABLES=" acc_trans ap ar assembly audittrail business chart + custom_field_catalog custom_table_catalog customer customertax + defaults department dpt_trans employee exchangerate gifi gl inventory + invoice jcitems language makemodel oe orderitems parts partscustomer + partsgroup partstax partsvendor pricegroup project recurring + recurringemail recurringprint session shipto sic status tax + transactions translation vendor vendortax warehouse yearend" + +SETUPSET=${mktmp}/create_set.slonik + +echo "include <${PREAMBLE}>;" > $SETUPSET +echo "create set (id=1, origin=1, comment='${CLUSTER} Tables and Sequences');" >> $SETUPSET + +tnum=1 + +for table in `echo $TABLES`; do + echo "set add table (id=${tnum}, set id=1, origin=1, fully qualified name='public.${table}', comment='${CLUSTER} table ${table}');" >> $SETUPSET + tnum=`expr ${tnum} + 1` +done + +snum=1 +for seq in `echo $SEQUENCES`; do + echo "set add sequence (id=${snum}, set id=1, origin=1, fully qualified name='public.${seq}', comment='${CLUSTER} sequence ${seq}');" >> $SETUPSET + snum=`expr ${snum} + 1` +done + +NODEINIT=$mktmp/create_nodes.slonik +echo "include <${PREAMBLE}>;" > $NODEINIT +echo "init cluster (id=1, comment='${CLUSTER} node 1');" >> $NODEINIT + +node=2 +while : ; do + SUBFILE=$mktmp/subscribe_set_${node}.slonik + echo "include <${PREAMBLE}>;" > $SUBFILE + echo "store node (id=${node}, comment='${CLUSTER} subscriber node ${node}');" >> $NODEINIT + echo "subscribe set (id=1, provider=1, receiver=${node}, forward=yes);" >> $SUBFILE + if [ ${node} -ge ${NUMNODES} ]; then + break; + else + node=`expr ${node} + 1` + fi +done + +store_path + +echo " +$0 has generated Slony-I slonik scripts to initialize replication for LedgerSMB. + +Cluster name: ${CLUSTER} +Number of nodes: ${NUMNODES} +Scripts are in ${mktmp} +===================== +" +ls -l $mktmp + +echo " +===================== +Be sure to verify that the contents of $PREAMBLE very carefully, as +the configuration there is used widely in the other scripts. +===================== +=====================" + + + + + + + + + |