Well, I can think of one way we do it that may be an option for you... Journal replication.... our new fail over / continuity solution ensures that the speed of light does not impede us by caching the journals and also, when data is to be written, as it comes in, we make sure it gos to two places FIRST and written twice before it s committed. Heck I know you know this... :-) So it is possible to make sure your stuff is redundant FIRST before it is committed to the database or whatever. But yes, you're right, it is expensive. We bit a huge bullet when we implemented GoldenGate (which I mentioned before)
One problem we are looking at now is that if the data is corrupt to begin with, it will be written redundantly corrupt as well :-)) But then again, that is not what redundancy is all about.
I guess what I fail to understand is why if everything is redundant, does it have to be down. This is in no way a put down or anything. Just trying to understand why if there is another system in place, why [it] can not serve out images until the other is back. I don;t necessarily want to upload, but at least let visitors VIEW images already stored. Can you just stop MODS to the database but allow reads?
In any case, this may be better discussed in the wiki as you stated. You guys make it too easy to chat with you about such things. All in all, consider this just a geek talking shop... nothing negative in any way. I love my Smugmug
Comments
Diligence can only be exceeded by result...:lift
Thanks Smugmug.
blackholewon
Well, I can think of one way we do it that may be an option for you... Journal replication.... our new fail over / continuity solution ensures that the speed of light does not impede us by caching the journals and also, when data is to be written, as it comes in, we make sure it gos to two places FIRST and written twice before it s committed. Heck I know you know this... :-) So it is possible to make sure your stuff is redundant FIRST before it is committed to the database or whatever. But yes, you're right, it is expensive. We bit a huge bullet when we implemented GoldenGate (which I mentioned before)
One problem we are looking at now is that if the data is corrupt to begin with, it will be written redundantly corrupt as well :-)) But then again, that is not what redundancy is all about.
I guess what I fail to understand is why if everything is redundant, does it have to be down. This is in no way a put down or anything. Just trying to understand why if there is another system in place, why [it] can not serve out images until the other is back. I don;t necessarily want to upload, but at least let visitors VIEW images already stored. Can you just stop MODS to the database but allow reads?
In any case, this may be better discussed in the wiki as you stated. You guys make it too easy to chat with you about such things. All in all, consider this just a geek talking shop... nothing negative in any way. I love my Smugmug
http://manny.smugmug.com/