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What is SnapSync Over Delphix Sessions Protocol (DSP) (KBA1284)



Overview of changes made to SnapSync over Delphix Session Protocol (DSP)

  • The toolkit deployed on dSource hosts includes the JDK

  • A Java process will be launched during SnapSync that acts as a proxy on behalf of the Delphix Engine until the SnapSync is complete

  • Access to port 8415 on the Delphix Engine will be required from the dSource host in order to run SnapSync. Customers employing network firewalls may need to update their firewall configuration (see Network and Connectivity Requirements for more information)

SnapSync over DSP and its Benefits

DSP allows distributed applications to invoke remote methods as if they were local, instead of using SSH. DSP supports the Java language binding, which will allow Delphix to build arbitrarily complex workflows involving the hosts with the modularity, maintainability, and portability that Java provides.

As a DSP-based application, SnapSync automatically inherits the following benefits from the infrastructure:

  • Better resilience to transient network failures
  • Enhanced security with session authentication and optional encryption
  • Improved throughput and reduced bandwidth usage through compression

  • Data integrity through checksum support

  • Resource management through bandwidth throttling

  • Modularity and more robust error handling

  • Improved job monitoring and supportability

High level overview of the SnapSync architecture:

SnapSync over DSP.png

Backing Up Oracle Databases with DSP

SnapSync performs backup of the Oracle database through the standard RMAN interface. The change with DSP is that the backup data gathered by Oracle arrives at the Delphix backup process through each of the RMAN channels before they are delivered to the Delphix Engine via DSP. 

Example of Delphix Backup Process with DSP

[root@bbdhcp ~]# ps -ef
ora10205 23670 1 0 10:46 ? 00:00:02 /work/Delphix_COMMON_564d2a38_f153_c90b_645a_a7b98ae4d254_ora10205_host/java/jdk/bin/java -ea -jar /work/Delphix_COMMON_564d2a38_f153_c90b_645a_a7b98ae4d254_ora10205_host/client/dsp/client.jar
ora10205 25610 23670 0 10:51 ? 00:00:00 rman app/ora10205/product/10.2.0/db_1/bin/rman
ora10205 25620 25610 0 10:51 ? 00:00:00 oracledb10205 (DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))
ora10205 25883 25610 0 10:53 ? 00:00:00 oracledb10205 (DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))
[root@bbdhcp ~]# pstree
│ └─62*[{java}]

Monitoring SnapSync Processes

The status of the SnapSync process can also be monitored through job events and process tracking. SnapSync processes that can be actively monitored include:

  • Job progression (time and percentage)

  • Average throughput

  • Current connectivity to the host

  • Reporting on lost connectivity

SnapSync Wire Level Services: Checksum, Compression, Encryption

In the new SnapSync implementation, Delphix offers a number of wire level data services, such as data digest, compression, and encryption. The data digest computes a checksum of the data. In the unlikely event data is randomly corrupted over the wire, Delphix will be able to detect the corrupted data and re-transmit it only. The CPU overhead for data digest is very low and it is always enabled. Compression may boost throughput for bandwidth limited environments, and encryption is suitable for highly sensitive data and / or open network environments. Neither of these services consume CPU.


SnapSync and Backup Network Security

(for more information please see the Support KB article “Network Security with DSP”)

  • SnapSync uses secure network protocols such as DSP and SSH with strong authentication and optional encryption support

  • The Delphix backup process communicates with the external world via a secure DSP session only