Question about result caching about tiedot

[agoalofalife]

@frednomoon to record information on the disk is used mmap
therefore entry does not occur instantly,
perhaps this is the reason

quote

At the moment tiedot does not use a journal file, therefore it relies on operating system to periodically synchronize mapped file buffer with underlying storage device; this means, that in case of a system crash, you may lose several most recent document updates.

but maybe I'm wrong

[frednomoon]

@agoalofalife thanks for the quick response Ilya!

I'll expand on my explanation to say why I don't think that is the problem... In the situation I describe, service A adds a new Document which it is almost immediately able to read/ update etc. Despite service A being able to see the new document it has added, service B cannot see it. This situation persists until I restart service B (I have seen this happen for >5 minutes).

Also to be more specific in what I mean by "restart". I mean that the tiedot function openDB needs to be called, which I usually would do once upon starting the application.

I have solved the problem for now in my application by simply calling openDB again when I need service B to check for new information. But I am still interested to find out what is happening in the background!

[HouzuoGuo]

Hello @frednomoon.
I am sorry to say that this use case is not well supported. OpenDB function is very expensive to call, it may take up to several seconds to finish for a large collection, and there cannot be two DB instances operating under the same data directory.

For your use case, please consider running an HTTP service on the server A and let server B use HTTP client to query for the new document.

[agoalofalife]

I have not read the original code
I can try to guess again
maybe something is stored in memory, because the main use of using REST API
I think the addresses of the documents are stored in the buffer
you can write a function to fill or update the buffer
more details probably will answer @HouzuoGuo
In any case, good luck!

[frednomoon]

Thanks for the responses!