Many databases implement durability by writing all transactions into a transaction log that can be played back to recreate the system state right before a failure. A transaction can only be deemed committed after it is safely in the log.
Questions tagged [durability]
45 questions
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How to do atomic file write & fsync to stable storage on Linux?
I'm writing a specialized database-like thingie targeting Linux. It needs to support atomic and durable modification.
I'm trying to implement this using write-ahead logging, but having trouble figuring out how to properly atomically commit the log…
yuri kilochek
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What are posix/linux/filesystem durability guarantees for ordered file writes?
Suppose I have a (single-threaded) program that (exclusively) opens a large file and does two non-overlapping writes:
int fd = open(path, O_RDWR);
pwrite(fd, data1, size1, offset1);
pwrite(fd, data2, size2, offset2);
close(fd);
Are there any…
yuri kilochek
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Making redis durable with a slave redis queue
Maybe I am missing something, this seems too simple. Is it possible to make redis durable by having a master redis node duplicate data to a slave redis node?
My situation I have a REST endpoint which upon recieving a request from a client sticks the…
friartuck
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Testing durability by automatically killing a C program at file/line?
I'm writing a bit of software that uses the fsync() system call to ensure a file is persisted to disk. I've done this before, and I'm aware of various "gotchas" you need to be aware of (i.e., when replacing a file, you need to fsync() the file,…
magnus
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Why durable subscription can have only one active subscriber at a time
From official doc
At the cost of higher overhead, you can use the
Session.createDurableSubscriber method to create a durable subscriber.
A durable subscription can have only one active subscriber at a time
Can you explain why design was chosen…
gstackoverflow
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rabbitmq-server start losing data over durable queues
On windows, when I am using rabbitmq-server start/stop commands, data over the RabbitMQ durable queues are deleted. It seems queues are re-created when I start the RabbitMQ server.
If I use rabbitmqctl stop_app/start_app, I am not losing any data.…
melihcoskun
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What happens if a Publisher terminates before receive ack?
I want to ensure that certain kind of messages couldn't be lost, hence I should use Confirms (aka Publisher Acknowledgements).
The broker loses persistent messages if it crashes before said
messages are written to disk. Under certain conditions,…
gabrielgiussi
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Couchbase View Consistency
The following code guarantees that any given document will be saved in a durable manner to the active node in a Couchbase cluster, as well as replicated to 1 additional node:
cas, err := myBucket.UpsertDura(docToStore, valueToStore, 1, 1)
Given…
Paul Mooney
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What happens to Local SSD if the entire zone were to lose power?
What happens to data on local SSD if the entire google data center were to suffer a cataclysmic loss of power? When the compute engine instance comes back online eventually, will it still have the data on the Local SSD? It seems like it handles…
Eloff
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Really durable queue in RabbitMQ
I checked "Message durability" part of RabbitMQ tutorial. But it has this note:
Marking messages as persistent doesn't fully guarantee that a message
won't be lost. Although it tells RabbitMQ to save the message to disk,
there is still a short…
Guy Fawkes
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Can I specify CAS value and durability requirements together in a store operation?
I am using Couchbase .NET SDK 1.3.
The task is to store a value, provided the data under its key has not been modified in the DB since the value was read, and be sure the new value is persisted/replicated to a certain number of nodes. For…
Evgeny A.
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Durable network communication dilemma
Lets imagine that we have a bank and an ATM. They communicate over network, which could fail. Is it possible to create a scenario, where communication between them is 100% durable. In this case it means, that:
client withdrawn physical amount of…
Denis Kulagin
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Durably reordering values on disk
I have a large number (100s of millions) of fixed-size values stored in a random order on a disk. I have the same set of values stored in memory, in a different order. I need to store the values in the order they are in memory, on disk. The…
Max
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CouchDB's crash-only design is for durability,why?
When I research on couchDB's durability , I find that couchDB use crash-only design to get durability.But I don't know what's the relationship between crash-only and durability.
wuchang
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Is Journal + Majority 100% safe?
I have been reading a few articles on MongoDB fault tolerance, and some people complain it can never really be achieved with MongoDB (like in this article: http://hackingdistributed.com/2013/01/29/mongo-ft/), and this got be confused.
Can someone…
Flavien
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