Percona

Fix: safe_to_bootstrap: 1

# search for node with "safe_to_bootstrap: 1"
cat /var/lib/mysql/grastate.dat

killall mysqld
service mysql bootstrap-pxc
#/etc/init.d/mysql bootstrap-pxc
service mysql start
killall -9 mysqld
cat /var/lib/mysql/grastate.dat
mysqld_safe --wsrep-recover
service mysql status

service mysql start --wsrep-new-cluster
tail -f /var/log/mysqld.log

# n-th hosts
service mysql start



sed -i "/safe_to_bootstrap/s/0/1/" /var/lib/mysql/grastate.dat

https://www.percona.com/doc/percona-xtradb-cluster/LATEST/howtos/crash-recovery.html
# https://severalnines.com/blog/updated-how-bootstrap-mysql-or-mariadb-galera-cluster
killall -9 mysqld
cat /var/lib/mysql/grastate.dat
mysqld_safe --wsrep-new-cluster
service mysql restart

# restart start on remaining nodes

cat /var/lib/mysql/gvwstate.dat

Get cluster status

watch -d -n1 -x mysql -B -e "SHOW STATUS WHERE variable_name ='wsrep_local_state_comment' OR variable_name ='wsrep_cluster_size' OR variable_name ='wsrep_incoming_addresses' OR variable_name ='wsrep_cluster_status' OR variable_name ='wsrep_connected' OR variable_name ='wsrep_ready' OR variable_name ='wsrep_local_state_uuid' OR variable_name ='wsrep_cluster_state_uuid';"

Links
https://www.percona.com/doc/percona-xtradb-cluster/8.0/index.html
https://www.percona.com/blog/2014/09/01/galera-replication-how-to-recover-a-pxc-cluster/
https://pandorafms.com/docs/index.php?title=Pandora:Documentation_en:Percona_Cluster
https://www.claudiokuenzler.com/blog/494/galera-cluster-mysql-not-starting-failed-to-open-channel-reach-primary
https://www.clevernetsystems.com/troubleshooting-a-clustercontrol-mysql-pxc-cluster/

Oracle

CLI

${ORACLE_HOME}/bin/sqlplus -s user1/pass1 <

<strong>Show all tables</strong>
<code>
select table_name from all_tables;

Links
ORACLE Free and Open Source Software
http://oss.oracle.com/

Oracle Database 10g Express Edition
http://oss.oracle.com/oracle-database-xe.html

Oracle SQL Developer
http://oss.oracle.com/sqldeveloper.html

Backup
https://oracle-base.com/articles/11g/data-pump-enhancements-11gr1

su oracle -

$ crontab -l
MAILTO=foo@example.com
ORACLE_HOME=/oracle/app/product/11.2.0/dbhome_1

0 20 * * 0-5 ${ORACLE_HOME}/bin/expdp system/PASSWORD@INSTANCE full=y directory=backup compression=all dumpfile=INSTANCE.full.$(date -I).dmp logfile=INSTANCE.full.$(date -I).log
0 21 * * * find /oracle/backup -mtime +3 -name "INSTANCE.full.*" -exec rm {} \;

Export single schema

${ORACLE_HOME}/bin/expdp USER/PASS schemas=SCHEMA_NAME directory=backup dumpfile=INSTANCE.full.$(date -I).dmp logfile=INSTANCE.full.$(date -I).log

Import

export ORACLE_HOME=/usr/lib/oracle/xe/app/oracle/product/10.2.0/server
export ORACLE_SID=XE
${ORACLE_HOME}/bin/imp user1/pass1 FROMUSER=user2 TOUSER=user3 TABLES=table1,table2 file=${FILE} log=/tmp/imp.log

# schemas=schema1,schema2
# remap_schema=schema1:schema2
# remap_tablespace=user1:user2
# full=yes

/oracle/app/product/11.2.0/dbhome_1/bin/impdp user1/pass1 TABLES=table1,table2 TABLE_EXISTS_ACTION=REPLACE DUMPFILE=BACKUP:db1.full.dmp LOGFILE=BACKUP:imp.$(date -I).log

# docker
https://hub.docker.com/r/wnameless/oracle-xe-11g/

docker run -d -p 49160:22 -p 49161:1521 -v /storage/dpdump:/u01/app/oracle/admin/XE/dpdump wnameless/oracle-xe-11g
sshpass -p admin ssh root@localhost -p 49160

docker stop $(docker ps -q --filter ancestor=wnameless/oracle-xe-11g)

Webgui
https://db.example.com:1158/em/console/logon/logon

db