Temporary alias for xrootd internal traffic

Title

 Temporary alias for xrootd internal traffic

Submitted by

 Jyothish Thomas

Requested by

 Alastair Dewhurst

Summary

Problem

The new gateways do not have external ipv6 access due to pending network interventions that have delayed their deployments for multiple weeks. The current external gateways are under heavy load from the current traffic and cause functional test and job failures.

Proposed solution

Add an additional DNS round robin alias (internal.echo.stfc.ac.uk) that maps to the gateways pending deployment.
Add an iptables rule on the batch farm to redirect xrootd.echo.stfc.ac.uk and webdav.echo.stfc.ac.uk traffic to it instead. Direct transfers would take place without issues, and if the jobs perform tpc the traffic should go over ipv4 as the job containers are ipv4 only.

Urgency

 Urgent

Impact of successfully implementing the change

 Workernode load affecting external xrootd gateways will be diverted to a set of currently unused gateways, thereby reducing load related issues in production

Consultation

Type of Change

Link to Change Control master ticket (RT or JSM)

Details of testing carried out

Further tests required prior to implementation

Deployed/tested at other WLCG/EGEE site?

Can be phased in stages?

Implementation plan

Post implementation testing

Reversion plan in case of problems

Has this been successfully reviewed with production team against new service ticklist.

(This should be done for significant changes to services too).

Residual risk 1

Residual risk 2

Residual risk 3

Affected components

VOs likely to be affected

Impact on existing data

Impact on subsequent data