我们在Jelastic中管理多个Java + PostgreSQL环境。我们的PaaS提供商使用Jelastic平台5.4版。
在每种环境中，我们都有一个cron任务，该任务调用Shell脚本以通过pg_dump为PostgreSQL 9.4生成每日压缩的数据库备份。从字面上看，该脚本已经运行了多年，但是最近它停止工作了。脚本如下所示：
#!/bin/bash
DATE=`date +"%Y-%m-%d_%H-%M-%S"`
DB_NAME="my-backup"
FILE="$DB_NAME-$DATE.backup.gz"
BASE_DIR="/var/lib/jelastic/backup"
BACKUP_FILE_PATH=$BASE_DIR/$FILE
pg_dump --verbose --format=custom $DB_NAME | gzip > $BACKUP_FILE_PATH
最近唯一更改的内容与shared_buffers中postgresql.conf值的增加有关，这是我们根据Jelastic提供的指令执行的更改。我们确实尝试将shared_buffers上的更改撤消，以将其恢复为Jelastic环境的默认值，而对备份没有积极影响。
现在，生成的备份文件（压缩）只有20个字节长，整个备份过程比我们期望的要少得多的时间，因为我们的数据库很大（超过1.5GB）并且包含BLOB。从GZIP提取的文件为空。
在pg_dump的详细输出中，没有什么异常：
pg_dump: reading schemas
pg_dump: reading user-defined tables
pg_dump: reading extensions
pg_dump: reading user-defined functions
pg_dump: reading user-defined types
pg_dump: reading procedural languages
pg_dump: reading user-defined aggregate functions
pg_dump: reading user-defined operators
pg_dump: reading user-defined operator classes
pg_dump: reading user-defined operator families
pg_dump: reading user-defined text search parsers
pg_dump: reading user-defined text search templates
pg_dump: reading user-defined text search dictionaries
pg_dump: reading user-defined text search configurations
pg_dump: reading user-defined foreign-data wrappers
pg_dump: reading user-defined foreign servers
pg_dump: reading default privileges
pg_dump: reading user-defined collations
pg_dump: reading user-defined conversions
pg_dump: reading type casts
pg_dump: reading table inheritance information
pg_dump: reading event triggers
pg_dump: finding extension members
pg_dump: finding inheritance relationships
pg_dump: reading column info for interesting tables
pg_dump: finding the columns and types of table "databasechangeloglock"
pg_dump: finding the columns and types of table "databasechangelog"
pg_dump: finding the columns and types of table "compania"
pg_dump: finding default expressions of table "compania"
pg_dump: finding the columns and types of table "comprobante"
pg_dump: finding default expressions of table "comprobante"
pg_dump: finding the columns and types of table "estado_comprobante"
pg_dump: finding default expressions of table "estado_comprobante"
pg_dump: finding the columns and types of table "usuario"
pg_dump: finding default expressions of table "usuario"
pg_dump: finding the columns and types of table "clave_contingencia"
pg_dump: finding default expressions of table "clave_contingencia"
pg_dump: finding the columns and types of table "latido_integrador"
pg_dump: finding default expressions of table "latido_integrador"
pg_dump: finding the columns and types of table "comprobante_importado"
pg_dump: finding default expressions of table "comprobante_importado"
pg_dump: finding the columns and types of table "estado_comprobante_importado"
pg_dump: finding default expressions of table "estado_comprobante_importado"
pg_dump: finding the columns and types of table "tarea_comprobante_importado"
pg_dump: finding default expressions of table "tarea_comprobante_importado"
pg_dump: finding the columns and types of table "usuario_compania"
pg_dump: finding default expressions of table "usuario_compania"
pg_dump: flagging inherited columns in subtables
pg_dump: reading indexes
pg_dump: reading indexes for table "databasechangeloglock"
pg_dump: reading indexes for table "compania"
pg_dump: reading indexes for table "comprobante"
pg_dump: reading indexes for table "estado_comprobante"
pg_dump: reading indexes for table "usuario"
pg_dump: reading indexes for table "clave_contingencia"
pg_dump: reading indexes for table "latido_integrador"
pg_dump: reading indexes for table "comprobante_importado"
pg_dump: reading indexes for table "estado_comprobante_importado"
pg_dump: reading indexes for table "tarea_comprobante_importado"
pg_dump: reading indexes for table "usuario_compania"
pg_dump: reading constraints
pg_dump: reading foreign key constraints for table "compania"
pg_dump: reading foreign key constraints for table "comprobante"
pg_dump: reading foreign key constraints for table "estado_comprobante"
pg_dump: reading foreign key constraints for table "usuario"
pg_dump: reading foreign key constraints for table "clave_contingencia"
pg_dump: reading foreign key constraints for table "latido_integrador"
pg_dump: reading foreign key constraints for table "comprobante_importado"
pg_dump: reading foreign key constraints for table "estado_comprobante_importado"
pg_dump: reading foreign key constraints for table "tarea_comprobante_importado"
pg_dump: reading foreign key constraints for table "usuario_compania"
pg_dump: reading triggers
pg_dump: reading triggers for table "compania"
pg_dump: reading triggers for table "comprobante"
pg_dump: reading triggers for table "estado_comprobante"
pg_dump: reading triggers for table "usuario"
pg_dump: reading triggers for table "clave_contingencia"
pg_dump: reading triggers for table "latido_integrador"
pg_dump: reading triggers for table "comprobante_importado"
pg_dump: reading triggers for table "estado_comprobante_importado"
pg_dump: reading triggers for table "tarea_comprobante_importado"
pg_dump: reading triggers for table "usuario_compania"
pg_dump: reading rewrite rules
pg_dump: reading large objects
pg_dump: reading dependency data
pg_dump: saving encoding = UTF8
pg_dump: saving standard_conforming_strings = on
pg_dump: saving database definition
此外，无法在Jelastic上访问的PostgreSQL 9.4日志也没有显示任何相关消息，这些消息可能无法为我们提供线索。
为试图“解决”此问题，我们执行了包括vacuumlo和vacuumdb --full在内的PostgreSQL维护程序，无济于事。备份文件有足够的可用存储空间，因此这不应成为问题的原因。
关于为什么会发生这种情况的任何想法？我们应该寻找什么，在哪里？由于这是一个至关重要的问题，我们希望您能提出一些建议。
答案 0 :(得分：1)
您需要做的第一件事是更改文件pg_hba.conf（允许通过套接字进行无密码连接）
CT-42366 ~# cat ./backup.sh
local all all trust
host all all 127.0.0.1/32 ident
host all all ::1/128 ident
host all all 0.0.0.0/0 md5
之后，重新启动“ postgresql”服务：
service postgresql restart
然后，如果您对数据库的登录名不同于“ root”，请使用以下修改的脚本：
CT-42366 ~# cat ./backup.sh
#!/bin/bash
DATE=date +"%Y-%m-%d_%H-%M-%S"
DB_NAME="db_name"
LOGIN="db_login"
FILE="$DB_NAME-$DATE.backup.gz"
BASE_DIR="/var/lib/jelastic/backup"
BACKUP_FILE_PATH=$BASE_DIR/$FILE
pg_dump --user=$LOGIN --format=custom --dbname=$DB_NAME | gzip >
$BACKUP_FILE_PATH
我们希望这可以帮助您解决问题。