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Senior Consultant at GAIVOTA consulting SA
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Question Enrico Parisi · May 2, 2025

DICOM, Mirror and StorageLocation

Is anyone using DICOM Interoperability in IRIS for Health configured in Mirror?

I'm asking because I'm not sure how to handle where the DICOM messages are stored.

For some reason DICOM use the filesystem to store raw messages, the directory used can be configured in the StorageLocation production settings, obviously this is a big issue if/when a mirror failover occur.

Unfortunately in IRIS it's not possible to change the DICOM storage from file stream to global stream.

Has anyone came across this issue?

Comments

Jeffrey Drumm · May 2, 2025

Use a NAS share that's mounted at the same location on both servers. There are other options involving SANs and mirrored filesystems but they're generally a bit pricier.

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Enrico Parisi  May 2, 2025 to Jeffrey Drumm

But...this is supposed to be a High Availability environment/configuration, a NAS would add a single point of failure along with the network between IRIS and NAS, there are also performance and maybe security consideration IMHO.

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Jeffrey Drumm  May 2, 2025 to Enrico Parisi

It's less risky than losing access to the images completely on a failover, no?

If you want true on-prem HA/Business Continuity, you need to get a systems engineer involved. I'm not one, at least anymore 😁

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Luis Angel Pérez Ramos · May 3, 2025

Well, I guess that the reason for the storage of DICOM images out of the database is the huge size of these images. 

I was working for a time for a VNA provider and many studies composed by hundred of DICOM images usually weighted more than 4 and 5 GB.

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Enrico Parisi  May 3, 2025 to Luis Angel Pérez Ramos

It depends on use case.
In my case we use DICOM integration to orchestrate archiving of studies between AETs, so we use commands like CFIND, CMOVE etc. and never download a study.

At the moment we have 290K+ files, the biggest is 1KB.
I think that even when you download studies having the option to use global streams instead of files would be extremely useful in a mirror configuration.

Depending on the environment, having an high availability single shared directory between mirror members can be expensive from MANY point of view (resources, configuration, maintenance, backup, security, etc.).
When an async DR is in place things get even more complicated.

As it stands, using IRIS DICOM interoperability in mirror configuration it's a nightmare.

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Evgeny Shvarov  May 4, 2025 to Enrico Parisi

Is it very complex to develop a new DICOM adapter that will use global streams instead?

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Enrico Parisi  May 4, 2025 to Evgeny Shvarov

Is it very complex to develop a new DICOM adapter that will use global streams instead?

It should not for InterSystems.

Note that the DICOM adapter/implementation in IRIS use some external ISC undocumented libraries.

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