VTG team share review

1. Cisco Confidential 1© 2013 Cisco and/or its affiliates. All rights reserved.
NCS Replication
and Recovery
Rajesh Tripurneni
Matthew Fertitta
CTG Build Team
Rally U.S. 137932

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Replication Analysis Questions
• How will teams at remote sites handle the following
operations in a streamlined and efficient way?:
- Pulling down the entire code base (cloning)
- Pulling down the latest changes (pulling)
- Pushing changes into the “master” origin
• How can we use replication to help us with disaster
recovery or other outages?

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Option 1 – Single Pull/Push Site
• Remote sites pull from and push to the master
origin (RCDN).
• Advantages
- Only one source to get the code from
• Disadvantages
- Takes a long time to pull down the code
- Requires a lot of bandwidth to pull down the code

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Option 2 – Remote Tracking Branch
(RTB)
• Create a RTB in RCDN to help control commits
• Advantages
• Disadvantages
- Not recommended or supported by the SCMCI team
(http://wikicentral.cisco.com/display/PROJECT/High+availabil
ity+with+Git+using+Remote+Branch+Tracking)

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Option 3 – Cloned Repos at Remote
Sites
• Remote sites pull from a remote origin at their site
and push to the master origin (RCDN).
• Advantages
- Pulling down the code is faster, since the clone is local
- Having only one Gerrit location to push to reduces or
eliminates synchronization errors in the master repos
• Disadvantages
- More setup involved

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Option 4 – Separate Repo Setup at Remote
Sites
• Remote sites pull and push from a remote origin at
their site. Periodic pushes occur between the
remote origin and the master origin.
• Advantages
- Pulling down and pushing back code is faster, since the
origin is local
• Disadvantages
- Synchronization problems
- Increased merge conflicts

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Recommended Solution (Option 3)
Developer
workspace
(US)
Developer
workspace
(BGL)
NCS Gerrit
Server (RCDN)
gpull
gpull
NCS repos
(master copy)(RCDN)
g
i
t
p
u
ll
NCS repos
(clone)(BGL)

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Recommended Solution for Recovery
NCS repos
(master copy)(RCDN)
NCS repos
(clone)(BGL)
NCS repos
(clone)(RTP)
NCS repos
(clone)(SJC)
git pull

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Option 3 – Implementation
Considerations
• Replication for Code Development
- Update the gpull and gpush wrapper scripts so that
they automatically pull and push from the correct
origins, based off of the user’s location
- Set up a Gerrit trigger on the NCS Gerrit server which
notifies remote clones to initiate a git pull, so that they
can be updated
• Replication for Recovery
- Reach out to the SCMCI team to help get IT supported
Git clones set up
(http://wikicentral.cisco.com/display/PROJECT/SCMCI
+-+Centrally+Supported+Git)
- Set up a polling or transaction based method of
updating the Git clones

10. Thank
you.