Linux 上的日志传送入门

  • 项目

适用于：SQL Server - Linux

日志传送是一种 SQL Server 高可用性 (HA) 配置，支持将数据库从主服务器复制到一个或多个辅助服务器上。 日志传送可使源数据库中的备份文件还原到辅助服务器。 主服务器会定期创建事务日志备份，辅助服务器会还原备份，同时更新数据库的次要副本。

Diagram showing the log shipping workflow.

如前面的关系图所示，日志传送过程包含以下步骤：

  • 在 SQL Server 主实例上备份事务日志文件
  • 将事务日志备份文件通过网络复制到一个或多个辅助 SQL Server 实例
  • 还原辅助 SQL Server 实例上的事务日志备份文件

必备条件

使用 CIFS 为日志传送设置网络共享

注意

本教程使用 CIFS 和 Samba 设置网络共享。

配置主服务器

  1. 使用以下命令安装 Samba：

    • 对于 Red Hat Enterprise Linux (RHEL)：

      sudo yum -y install samba

    • 对于 Ubuntu：

      sudo apt-get install samba

  2. 创建用于存储日志传送的日志的目录，并为 mssql 用户提供所需权限：

    mkdir /var/opt/mssql/tlogs
chown mssql:mssql /var/opt/mssql/tlogs
chmod 0700 /var/opt/mssql/tlogs

  3. 编辑 /etc/samba/smb.conf 文件（需要根权限）并添加以下部分：

    [tlogs]
path=/var/opt/mssql/tlogs
available=yes
read only=yes
browsable=yes
public=yes
writable=no

  4. 为 Samba 创建 mssql 用户：

    sudo smbpasswd -a mssql

  5. 重启 Samba 服务：

    sudo systemctl restart smbd.service nmbd.service

配置辅助服务器

  1. 可以使用以下命令安装 CIFS 类：

    • 对于 RHEL：

      sudo yum -y install cifs-utils

    • 对于 Ubuntu：

      sudo apt-get install cifs-utils

  2. 创建文件以存储凭据。 在本例中，我们使用 /var/opt/mssql/.tlogcreds。 使用最近为 mssql Samba 帐户设置的密码并替换 <domain>：

    username=mssql
domain=<domain>
password=<password>

  3. 运行以下命令创建空目录，用于装载并正确设置权限和所有权

    mkdir /var/opt/mssql/tlogs
sudo chown root:root /var/opt/mssql/tlogs
sudo chmod 0550 /var/opt/mssql/tlogs
sudo chown root:root /var/opt/mssql/.tlogcreds
sudo chmod 0660 /var/opt/mssql/.tlogcreds

  4. 将此行添加到 etc/fstab 以保留共享。 将 <ip_address_of_primary_server> 替换为适当的值：

    //<ip_address_of_primary_server>/tlogs /var/opt/mssql/tlogs cifs credentials=/var/opt/mssql/.tlogcreds,ro,uid=mssql,gid=mssql 0 0

  5. 装载共享：

    sudo mount -a

使用 Transact-SQL 设置日志传送

  1. 在主服务器上备份数据库：

    BACKUP DATABASE SampleDB TO DISK = '/var/opt/mssql/tlogs/SampleDB.bak'
GO

  2. 在主服务器上配置日志传送：

    DECLARE @LS_BackupJobId AS UNIQUEIDENTIFIER;
DECLARE @LS_PrimaryId AS UNIQUEIDENTIFIER;
DECLARE @SP_Add_RetCode AS INT;

EXECUTE @SP_Add_RetCode = master.dbo.sp_add_log_shipping_primary_database
    @database = N'SampleDB',
    @backup_directory = N'/var/opt/mssql/tlogs',
    @backup_share = N'/var/opt/mssql/tlogs',
    @backup_job_name = N'LSBackup_SampleDB',
    @backup_retention_period = 4320,
    @backup_compression = 2,
    @backup_threshold = 60,
    @threshold_alert_enabled = 1,
    @history_retention_period = 5760,
    @backup_job_id = @LS_BackupJobId OUTPUT,
    @primary_id = @LS_PrimaryId OUTPUT,
    @overwrite = 1;

IF (@@ERROR = 0 AND @SP_Add_RetCode = 0)
BEGIN
    DECLARE @LS_BackUpScheduleUID AS UNIQUEIDENTIFIER;
    DECLARE @LS_BackUpScheduleID AS INT;

    EXECUTE msdb.dbo.sp_add_schedule
        @schedule_name = N'LSBackupSchedule',
        @enabled = 1,
        @freq_type = 4,
        @freq_interval = 1,
        @freq_subday_type = 4,
        @freq_subday_interval = 15,
        @freq_recurrence_factor = 0,
        @active_start_date = 20170418,
        @active_end_date = 99991231,
        @active_start_time = 0,
        @active_end_time = 235900,
        @schedule_uid = @LS_BackUpScheduleUID OUTPUT,
        @schedule_id = @LS_BackUpScheduleID OUTPUT;

    EXECUTE msdb.dbo.sp_attach_schedule
        @job_id = @LS_BackupJobId,
        @schedule_id = @LS_BackUpScheduleID;

    EXECUTE msdb.dbo.sp_update_job @job_id = @LS_BackupJobId, @enabled = 1;
END

EXECUTE master.dbo.sp_add_log_shipping_alert_job;

EXECUTE master.dbo.sp_add_log_shipping_primary_secondary
    @primary_database = N'SampleDB',
    @secondary_server = N'<ip_address_of_secondary_server>',
    @secondary_database = N'SampleDB',
    @overwrite = 1;

  3. 在辅助服务器上还原数据库：

    RESTORE DATABASE SampleDB
FROM DISK = '/var/opt/mssql/tlogs/SampleDB.bak'
WITH NORECOVERY;

  4. 在辅助服务器上配置日志传送：

    DECLARE @LS_Secondary__CopyJobId AS UNIQUEIDENTIFIER;
DECLARE @LS_Secondary__RestoreJobId AS UNIQUEIDENTIFIER;
DECLARE @LS_Secondary__SecondaryId AS UNIQUEIDENTIFIER;
DECLARE @LS_Add_RetCode AS INT;

EXECUTE @LS_Add_RetCode = master.dbo.sp_add_log_shipping_secondary_primary
    @primary_server = N'<ip_address_of_primary_server>',
    @primary_database = N'SampleDB',
    @backup_source_directory = N'/var/opt/mssql/tlogs/',
    @backup_destination_directory = N'/var/opt/mssql/tlogs/',
    @copy_job_name = N'LSCopy_SampleDB',
    @restore_job_name = N'LSRestore_SampleDB',
    @file_retention_period = 4320,
    @overwrite = 1,
    @copy_job_id = @LS_Secondary__CopyJobId OUTPUT,
    @restore_job_id = @LS_Secondary__RestoreJobId OUTPUT,
    @secondary_id = @LS_Secondary__SecondaryId OUTPUT

IF (@@ERROR = 0 AND @LS_Add_RetCode = 0)
BEGIN
    DECLARE @LS_SecondaryCopyJobScheduleUID AS UNIQUEIDENTIFIER;
    DECLARE @LS_SecondaryCopyJobScheduleID AS INT;

    EXECUTE msdb.dbo.sp_add_schedule
        @schedule_name = N'DefaultCopyJobSchedule',
        @enabled = 1,
        @freq_type = 4,
        @freq_interval = 1,
        @freq_subday_type = 4,
        @freq_subday_interval = 15,
        @freq_recurrence_factor = 0,
        @active_start_date = 20170418,
        @active_end_date = 99991231,
        @active_start_time = 0,
        @active_end_time = 235900,
        @schedule_uid = @LS_SecondaryCopyJobScheduleUID OUTPUT,
        @schedule_id = @LS_SecondaryCopyJobScheduleID OUTPUT;

    EXECUTE msdb.dbo.sp_attach_schedule
        @job_id = @LS_Secondary__CopyJobId,
        @schedule_id = @LS_SecondaryCopyJobScheduleID;

    DECLARE @LS_SecondaryRestoreJobScheduleUID AS UNIQUEIDENTIFIER;
    DECLARE @LS_SecondaryRestoreJobScheduleID AS INT;

    EXECUTE msdb.dbo.sp_add_schedule
        @schedule_name = N'DefaultRestoreJobSchedule',
        @enabled = 1,
        @freq_type = 4,
        @freq_interval = 1,
        @freq_subday_type = 4,
        @freq_subday_interval = 15,
        @freq_recurrence_factor = 0,
        @active_start_date = 20170418,
        @active_end_date = 99991231,
        @active_start_time = 0,
        @active_end_time = 235900,
        @schedule_uid = @LS_SecondaryRestoreJobScheduleUID OUTPUT,
        @schedule_id = @LS_SecondaryRestoreJobScheduleID OUTPUT;

    EXECUTE msdb.dbo.sp_attach_schedule
        @job_id = @LS_Secondary__RestoreJobId,
        @schedule_id = @LS_SecondaryRestoreJobScheduleID;
END

DECLARE @LS_Add_RetCode2 AS INT;

IF (@@ERROR = 0 AND @LS_Add_RetCode = 0)
BEGIN
    EXECUTE @LS_Add_RetCode2 = master.dbo.sp_add_log_shipping_secondary_database
        @secondary_database = N'SampleDB',
        @primary_server = N'<ip_address_of_primary_server>',
        @primary_database = N'SampleDB',
        @restore_delay = 0,
        @restore_mode = 0,
        @disconnect_users = 0,
        @restore_threshold = 45,
        @threshold_alert_enabled = 1,
        @history_retention_period = 5760,
        @overwrite = 1;
END

IF (@@ERROR = 0 AND @LS_Add_RetCode = 0)
BEGIN
    EXECUTE msdb.dbo.sp_update_job
        @job_id = @LS_Secondary__CopyJobId,
        @enabled = 1;

    EXECUTE msdb.dbo.sp_update_job
        @job_id = @LS_Secondary__RestoreJobId,
        @enabled = 1;
END

验证日志传送是否正常运行

  1. 通过在主服务器上启动以下作业来验证日志传送是否正常运行：

    USE msdb;
GO

EXECUTE dbo.sp_start_job N'LSBackup_SampleDB';
GO

  2. 通过在辅助服务器上启动以下作业来验证日志传送是否正常运行：

    USE msdb;
GO

EXECUTE dbo.sp_start_job N'LSCopy_SampleDB';
GO

EXECUTE dbo.sp_start_job N'LSRestore_SampleDB';
GO

  3. 通过执行以下命令验证日志传送故障转移是否正常运行：

    警告

    此命令将使辅助数据库处于联机状态并中断日志传送配置。 运行此命令后，将需要重新配置日志传送。

    RESTORE DATABASE SampleDB WITH RECOVERY;

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