To my knowledge, DD replication is asynchronous. I don't remember seeing option to control when or how frequent replication is done, but I assume this depends on algorithm which takes into account number of sessions and how busy DDFS is on both sides.
1. A snapshot is created at the source of the MTree replication context. This snapshot is compared to the last snapshot and the changes are sent across to the destination.
2. On the destination, the MTree will be updated but the files will not be exposed to the user until ALL the changes for the latest snapshot are received.
The above steps will be repeated every time a snapshot is created on the MTree which can occur in one of the two ways:
1. When the replication lag is more than 15 minutes and there is no snapshot being currently replicated (system-generated-periodic-snapshots)
2. At user-specified times (for example after the completion of a backup job) (user-created-snapshots)
Please mark my answer as correct/helpful answer if it helps.
Thank you Kevin. I have tested on our DataDomain and your answer was very usefull.
If the customer want's DataDomains in replication to be in sync with less that 15 minutes then the only solutuin is to create a user snapshots.
If the requrement for the replication lag is one munute, then we must create a user snapshot every minute with a retention for 1 day. Less then 1 minte replication lag is not possible, right?
What do you think. Is creating so many snapshots a good idea?
Could you explain the need to have the replication be synced less than 15 minutes? I have spoken with our replication experts and it is set to run in 15 minute intervals. There isn't a way to increase the kick off time (most likely due to pre-replication processes that need to run). Let me know if I can be of any further assistance.
ble1
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14.3K Posts
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February 13th, 2014 00:00
To my knowledge, DD replication is asynchronous. I don't remember seeing option to control when or how frequent replication is done, but I assume this depends on algorithm which takes into account number of sessions and how busy DDFS is on both sides.
o17Uu33DCF12520
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1.1K Posts
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February 13th, 2014 17:00
MTree replication involves the following steps:
1. A snapshot is created at the source of the MTree replication context. This snapshot is compared to the last snapshot and the changes are sent across to the destination.
2. On the destination, the MTree will be updated but the files will not be exposed to the user until ALL the changes for the latest snapshot are received.
The above steps will be repeated every time a snapshot is created on the MTree which can occur in one of the two ways:
1. When the replication lag is more than 15 minutes and there is no snapshot being currently replicated (system-generated-periodic-snapshots)
2. At user-specified times (for example after the completion of a backup job) (user-created-snapshots)
Please mark my answer as correct/helpful answer if it helps.
dejan4
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13 Posts
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February 14th, 2014 00:00
Thank you Kevin. I have tested on our DataDomain and your answer was very usefull.
If the customer want's DataDomains in replication to be in sync with less that 15 minutes then the only solutuin is to create a user snapshots.
If the requrement for the replication lag is one munute, then we must create a user snapshot every minute with a retention for 1 day. Less then 1 minte replication lag is not possible, right?
What do you think. Is creating so many snapshots a good idea?
PatrickBetts
1 Rookie
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116 Posts
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February 18th, 2014 10:00
Dejan,
Could you explain the need to have the replication be synced less than 15 minutes? I have spoken with our replication experts and it is set to run in 15 minute intervals. There isn't a way to increase the kick off time (most likely due to pre-replication processes that need to run). Let me know if I can be of any further assistance.
Best Regards,
Patrick