第一次做postgres复制——不工作

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这是我第一次在已经复制到服务器的生产服务器上配置复制。我正在添加一个额外的服务器。复制在现有环境中工作，但我添加的附加服务器不工作。由于我不想破坏现有的复制，因此我在主服务器上为附加服务器创建了一个新用户。这是 master 和 slave 上的 9.3.5 版本。

psql -c "CREATE USER rep REPLICATION LOGIN CONNECTION LIMIT 1 ENCRYPTED PASSWORD 'yourpassword';"

在slave上我创建了一个recovery文件，放到data目录下

standby_mode = 'on'
primary_conninfo = 'host=master_IP_address port=5432 user=rep 
password=yourpassword'
trigger_file = '/tmp/postgresql.trigger.5432'

在主服务器上，我开始了初始备份。

psql -c "select pg_start_backup('initial_backup');"

通过 rsync 复制数据。

rsync -cva --inplace --exclude=*pg_xlog* /var/lib/postgresql/9.1/main/ slave_IP_address:/var/lib/postgresql/9.1/main/

rsync 完成后，我发出以下命令。

psql -c "select pg_stop_backup();"

主服务器 - posgresql.conf

listen_addresses = '*'           

max_connections = 1000                  
unix_socket_directories = ''           


shared_buffers = 1024MB                 

temp_buffers = 1024MB                   
work_mem = 64MB                         
maintenance_work_mem = 512MB            
max_stack_depth = 31MB                  

wal_level = hot_standby                 


wal_buffers = -1                         

checkpoint_segments = 512                
checkpoint_timeout = 1h                 

# - Archiving -

archive_mode = on               

archive_command = 'cd .'

max_wal_senders = 5             

主服务器 - pg_hba.conf

# TYPE  DATABASE        USER            ADDRESS                 METHOD

# "local" is for Unix domain socket connections only
local   all             all                                        trust
# IPv4 local connections:
host    all             all              127.0.0.1/8               trust
host    all             all              192.168.10.10/32          trust
host    all             all              ny-node0.xxx.net          trust
# below is the existing replication server that works.
host    all             all              ny-node1.xxx.net          trust

# IPv6 local connections:
host    all             all             ::1/128                    trust

# Allow replication connections from localhost, by a user with the
# replication privilege.

local   replication     postgres                                trust
host    replication     postgres        127.0.0.1/8             trust

host    replication     postgres        ny-node1.xxx.net        trust
host    replication     rep             IP-OF-NEW-SLAVE/32      trust   
host    replication     postgres        IP-OF-MASTER/32         trust

从属 postgresql.conf

listen_addresses = '*' 
max_connections = 100                   
shared_buffers = 128MB                 
wal_level = hot_standby                 
archive_command = 'cd .'                 
logfile segment
max_wal_senders = 1             
hot_standby = on                
hot_standby_feedback = on               
wal_receiver_timeout = 60s              
log_destination = 'stderr'              
logging_collector = on          
log_directory = 'pg_log'                 
log_filename = 'postgresql-%Y-%m-%d_%H%M%S.log' 
log_timezone = 'UTC'
datestyle = 'iso, mdy'
timezone = 'UTC'
lc_messages = 'en_US.UTF-8'                      
lc_monetary = 'en_US.UTF-8'                      

lc_numeric = 'en_US.UTF-8'                        
lc_time = 'en_US.UTF-8'                         
default_text_search_config = 'pg_catalog.english'

从机的pg_hba.conf

# TYPE  DATABASE        USER            ADDRESS                 METHOD

# "local" is for Unix domain socket connections only
local   all             all                                     trust
# IPv4 local connections:
host    all             all             127.0.0.1/32            trust
# IPv6 local connections:
host    all             all             ::1/128                 trust
# Allow replication connections from localhost, by a user with the
# replication privilege.
#local   replication     postgres                                md5
host    replication     rep             IP-OF-MASTER/32        trust
#host    replication     postgres        ::1/128                 md5

我在 master 和 slave 上重新启动了 postgres，当我在 master 上创建数据库时，它不会复制到新的 slave。

我取得了一些进展（更新）

我调整了从属服务器上的 pg_hba.conf，只留下了与我为复制创建的新用户关联的行，称为“rep”。

#local   replication     rep                                     md5
host    replication      rep             ip_of_slave/32        trust
host    replication      rep             ip_of_master/32       trust

我还调整了我的 recovery.conf 并将其放在数据目录中。 由于我主从之间是信任关系，所以我把recovery.conf中的密码去掉了。

standby_mode = 'on'
primary_conninfo = 'host=ip_of_master port=5432 user=rep'
trigger_file = '/tmp/postgresql.trigger.5432'

现在我的日志显示：

LOG:  database system was shut down in recovery at 2019-09-02 20:02:04 UTC
LOG:  entering standby mode
LOG:  contrecord is requested by 26/78000028
LOG:  started streaming WAL from primary at 26/78000000 on timeline 7
LOG:  contrecord is requested by 26/78000028
FATAL:  terminating walreceiver process due to administrator command
LOG:  contrecord is requested by 26/78000028
LOG:  contrecord is requested by 26/78000028
LOG:  contrecord is requested by 26/78000028
LOG:  contrecord is requested by 26/78000028
LOG:  contrecord is requested by 26/78000028

Answer 1

看来你在把recovery.conf放到data目录之前就启动了slave服务器。在这种情况下，PostgreSQL 将在恢复后作为独立数据库出现，而不是成为备用服务器。

一旦发生这种情况，你必须丢弃从属服务器并重新开始。

正确的操作顺序是：

• SELECT pg_start_backup('label');

• 执行rsync

• SELECT pg_stop_backup();

• 将recovery.conf和standby_mode = 'on'放入slave的数据目录

• 启动从站