# Dragonfly Technical **URL:** https://dragonfly.discourse.group/c/technical/5.md [Latest](https://dragonfly.discourse.group/latest.md) · [Categories](https://dragonfly.discourse.group/categories.md) · [Tags](https://dragonfly.discourse.group/tags.md) --- ## [Error training model training model(s) – Pre-trained 2.5D (3 slices) U-Net Depth 5](https://dragonfly.discourse.group/t/error-training-model-training-model-s-pre-trained-2-5d-3-slices-u-net-depth-5/335)
**Author:** [@Valdenilson](https://dragonfly.discourse.group/u/Valdenilson)\ **Replies:** 0\ **Last updated:** [February 24, 2026, 1:58pm UTC](https://dragonfly.discourse.group/t/error-training-model-training-model-s-pre-trained-2-5d-3-slices-u-net-depth-5/335 "2026-02-24T13:58:39Z")
We are currently performing training for particulate organic matter (POM) segmentation using the Segmentation Wizard. Specifically, we are using the Model Generation Strategy Pre-trained 2.5D (3 slices) U-Net Depth 5. Ho… --- ## [Unusual snapshot behaviour](https://dragonfly.discourse.group/t/unusual-snapshot-behaviour/332)
**Author:** [@adochan](https://dragonfly.discourse.group/u/adochan)\ **Replies:** 3\ **Last updated:** [February 17, 2026, 3:15pm UTC](https://dragonfly.discourse.group/t/unusual-snapshot-behaviour/332 "2026-02-17T15:15:21Z")
Hi there, We are currently deploying multiple dragonfly clusters which are configured to snapshot to S3. We are seeing a very odd problem with one of those clusters. We have created a bucket - let’s call it df-snapshot… --- ## [RedisSemanticCache with LangChain not working after migrating from Redis to Dragonfly](https://dragonfly.discourse.group/t/redissemanticcache-with-langchain-not-working-after-migrating-from-redis-to-dragonfly/330)
**Author:** [@blancamartnez01](https://dragonfly.discourse.group/u/blancamartnez01)\ **Replies:** 1\ **Last updated:** [February 3, 2026, 9:38am UTC](https://dragonfly.discourse.group/t/redissemanticcache-with-langchain-not-working-after-migrating-from-redis-to-dragonfly/330 "2026-02-03T09:38:49Z")
Hi everyone, I’m running into an issue after migrating from Redis to Dragonfly and was wondering if anyone has experienced something similar. I previously had a system working correctly using Redis together with LangC… --- ## [Table\_used\_memory metric information](https://dragonfly.discourse.group/t/table-used-memory-metric-information/325)
**Author:** [@nunodio](https://dragonfly.discourse.group/u/nunodio)\ **Replies:** 2\ **Last updated:** [December 2, 2025, 5:50pm UTC](https://dragonfly.discourse.group/t/table-used-memory-metric-information/325 "2025-12-02T17:50:33Z")
Hello everyone, I’m running a Dragonfly setup on Kubernetes with a Master/Replica configuration. I’ve noticed a significant discrepancy in the memory usage between the two instances. Specifically, the table\_used\_memory … --- ## [DragonFly RAM Entries and SSD Entries](https://dragonfly.discourse.group/t/dragonfly-ram-entries-and-ssd-entries/316)
**Author:** [@thangaprakash](https://dragonfly.discourse.group/u/thangaprakash)\ **Replies:** 1\ **Last updated:** [November 18, 2025, 7:47am UTC](https://dragonfly.discourse.group/t/dragonfly-ram-entries-and-ssd-entries/316 "2025-11-18T07:47:11Z")
3 VMs – Each VM 8 vCPU, 32 GB, SSD Storage 250GB OS - 6.1.148-173.267.amzn2023.aarch64 DragonFly version : 1.34.2 MaxMemory : 20GB SSD Storage: 200GB 1 Master and 2 Replicas with 3 Sentinels Sentinel version : 7.2… --- ## [M\_replace\_aux Error with DragonFly 1.34.2](https://dragonfly.discourse.group/t/m-replace-aux-error-with-dragonfly-1-34-2/317)
**Author:** [@thangaprakash](https://dragonfly.discourse.group/u/thangaprakash)\ **Replies:** 2\ **Last updated:** [October 29, 2025, 7:32pm UTC](https://dragonfly.discourse.group/t/m-replace-aux-error-with-dragonfly-1-34-2/317 "2025-10-29T19:32:46Z")
ct 27 19:54:58 ip-172-31-0-22 dragonfly\[78125\]: F20251027 19:54:57.888782 78133 init.cc:140\] Uncaught exception: basic\_string::\_ M\_replace\_aux Oct 27 19:55:00 ip-172-31-0-22 dragonfly\[78125\]: \*\*\* Check failure stack tr… --- ## [Flags Configurations Details were getting lost - 1.34.2](https://dragonfly.discourse.group/t/flags-configurations-details-were-getting-lost-1-34-2/319)
**Author:** [@thangaprakash](https://dragonfly.discourse.group/u/thangaprakash)\ **Replies:** 2\ **Last updated:** [October 29, 2025, 7:28pm UTC](https://dragonfly.discourse.group/t/flags-configurations-details-were-getting-lost-1-34-2/319 "2025-10-29T19:28:36Z")
When I set maxmemory using redis-cli with Config set maxmemory 25GB, I observed the current booted configurations were overwritten with single configuration. DragonFly version 1.34.2 /etc/dragonfly/dragonfly.flags.conf… --- ## [DragonFly Config File Support in v1.34.2 - Equivalent to Redis](https://dragonfly.discourse.group/t/dragonfly-config-file-support-in-v1-34-2-equivalent-to-redis/314)
**Author:** [@thangaprakash](https://dragonfly.discourse.group/u/thangaprakash)\ **Replies:** 2\ **Last updated:** [October 27, 2025, 8:04pm UTC](https://dragonfly.discourse.group/t/dragonfly-config-file-support-in-v1-34-2-equivalent-to-redis/314 "2025-10-27T20:04:43Z")
Starting journey with DragonFly version 1.34.2 … I am unable to provide dragonfly.conf (as that of redis) while starting the dragonfly service. (linux) I am able to provide “-–flagfile flags.conf” but it doesn’t suppor… --- ## [Is it possible to change maxmemory\_policy?](https://dragonfly.discourse.group/t/is-it-possible-to-change-maxmemory-policy/313)
**Author:** [@KleinenberG](https://dragonfly.discourse.group/u/KleinenberG)\ **Replies:** 2\ **Last updated:** [September 4, 2025, 6:52am UTC](https://dragonfly.discourse.group/t/is-it-possible-to-change-maxmemory-policy/313 "2025-09-04T06:52:20Z")
Hello! I see in the output INFO MEMORY: maxmemory\_policy:noeviction can i change this policy? 127.0.0.1:6379\> info server redis\_version:7.4.0 dragonfly\_version:df-v1.28.1 as far as I understand - no!? --- ## [DragonflyDB Active-Active (Multi-Master) Support in 2025?](https://dragonfly.discourse.group/t/dragonflydb-active-active-multi-master-support-in-2025/304)
**Author:** [@BelroDe](https://dragonfly.discourse.group/u/BelroDe)\ **Replies:** 4\ **Last updated:** [August 19, 2025, 10:27pm UTC](https://dragonfly.discourse.group/t/dragonflydb-active-active-multi-master-support-in-2025/304 "2025-08-19T22:27:06Z")
Hi everyone, I’m trying to clarify the current state of active-active / multi-master support in DragonflyDB as of 2025. Information online seems a bit confusing, especially with the introduction of DragonflyDB Swarm. S… --- ## [ASYNC flushes possible?](https://dragonfly.discourse.group/t/async-flushes-possible/297)
**Author:** [@bergfreund](https://dragonfly.discourse.group/u/bergfreund)\ **Replies:** 4\ **Last updated:** [August 11, 2025, 3:23pm UTC](https://dragonfly.discourse.group/t/async-flushes-possible/297 "2025-08-11T15:23:33Z")
We have previously emptied our databases in Redis using “flushDB ASYNC”. Dragonfly does not accept parameters for flushDB. However, “flushALL ASYNC” is accepted. The documentation does not mention this, however. So my … --- ## [Unable to restore from .dfs unless --force\_epoll=true](https://dragonfly.discourse.group/t/unable-to-restore-from-dfs-unless-force-epoll-true/295)
**Author:** [@hgorni](https://dragonfly.discourse.group/u/hgorni)\ **Replies:** 1\ **Last updated:** [July 17, 2025, 6:44pm UTC](https://dragonfly.discourse.group/t/unable-to-restore-from-dfs-unless-force-epoll-true/295 "2025-07-17T18:44:09Z")
My Dragonfly instance is configured with --cache\_mode and --maxmemory=160G , running on a GCP Compute Engine VM with 22 vCPUs and 176 GB of RAM (c3-highmem-22 , Intel Sapphire Rapids, x86\_64, Debian 6.1.140-1). I’ve not… --- ## [Memory usage keeps increasing after reaching --maxmemory limit](https://dragonfly.discourse.group/t/memory-usage-keeps-increasing-after-reaching-maxmemory-limit/294)
**Author:** [@hgorni](https://dragonfly.discourse.group/u/hgorni)\ **Replies:** 1\ **Last updated:** [July 17, 2025, 2:29pm UTC](https://dragonfly.discourse.group/t/memory-usage-keeps-increasing-after-reaching-maxmemory-limit/294 "2025-07-17T14:29:09Z")
I recently migrated from Redis to Dragonfly in my production environment, setting an instance with --cache\_mode and --maxmemory=160G . Everything works as expected at first, but as the memory usage approaches the limit, … --- ## [Strange behavior with ZRANGEBYSCORE](https://dragonfly.discourse.group/t/strange-behavior-with-zrangebyscore/247)
**Author:** [@Claire](https://dragonfly.discourse.group/u/Claire)\ **Replies:** 19\ **Last updated:** [February 9, 2025, 11:43am UTC](https://dragonfly.discourse.group/t/strange-behavior-with-zrangebyscore/247 "2025-02-09T11:43:41Z")
Hi! We have recently migrated from Redis to DragonflyDB, and we are experiencing some weird behavior with ZRANGEBYSCORE. Indeed, for one of our functionalities, we have sorted sets holding numeric identifiers that are … --- ## [Error message when loading session file](https://dragonfly.discourse.group/t/error-message-when-loading-session-file/250)
**Author:** [@Jenny](https://dragonfly.discourse.group/u/Jenny)\ **Replies:** 1\ **Last updated:** [February 4, 2025, 2:35am UTC](https://dragonfly.discourse.group/t/error-message-when-loading-session-file/250 "2025-02-04T02:35:24Z")
Every time I try to load the session file, I receive an error message stating that the session cannot be loaded. However, after clicking “Ok”, both Dragonfly and Wizard function normally despite the error. Why is this ha… --- ## [Replication with Redis causing error on sync](https://dragonfly.discourse.group/t/replication-with-redis-causing-error-on-sync/225)
**Author:** [@MikeB](https://dragonfly.discourse.group/u/MikeB)\ **Replies:** 2\ **Last updated:** [November 4, 2024, 2:52pm UTC](https://dragonfly.discourse.group/t/replication-with-redis-causing-error-on-sync/225 "2024-11-04T14:52:10Z")
I’ve tried searching online and in this forum for anything related to these 3 errors that keep repeating when trying to do an initial sync with Redis. I can’t find anything at all so I must be doing something wrong or I … --- ## [SSD Tiering and docker](https://dragonfly.discourse.group/t/ssd-tiering-and-docker/222)
**Author:** [@Maciek](https://dragonfly.discourse.group/u/Maciek)\ **Replies:** 6\ **Last updated:** [October 30, 2024, 2:39pm UTC](https://dragonfly.discourse.group/t/ssd-tiering-and-docker/222 "2024-10-30T14:39:53Z")
Hi, I’m new to Dragonfly, testing it to replace Redis. I’m unable to run Dragonfly in a docker container with ssd tiering enabled. Even the simplest case doesn’t work: docker run --network=host --ulimit memlock=-1 -v /… --- ## [Script is running out of memory](https://dragonfly.discourse.group/t/script-is-running-out-of-memory/217)
**Author:** [@intj9839](https://dragonfly.discourse.group/u/intj9839)\ **Replies:** 2\ **Last updated:** [October 7, 2024, 5:26pm UTC](https://dragonfly.discourse.group/t/script-is-running-out-of-memory/217 "2024-10-07T17:26:47Z")
Hi, we have a script that’s been running out of memory, and was wondering if Dragonfly DB has any options to modify how much memory a script is allowed to use: We didn’t run into this in our staging environment but r… --- ## [After migration from Redis to Dragonfly issues](https://dragonfly.discourse.group/t/after-migration-from-redis-to-dragonfly-issues/212)
**Author:** [@tejaswinikandra111](https://dragonfly.discourse.group/u/tejaswinikandra111)\ **Replies:** 5\ **Last updated:** [October 1, 2024, 3:51pm UTC](https://dragonfly.discourse.group/t/after-migration-from-redis-to-dragonfly-issues/212 "2024-10-01T15:51:15Z")
Hi, I have recently started using dragonfly just by replacing my redis docker image with dragonfly image, It’s running absolutely fine. But a few tasks which were working seemless on redis are not working in dragonfly. … --- ## [Getting this error: Failed to load TLS key](https://dragonfly.discourse.group/t/getting-this-error-failed-to-load-tls-key/207)
**Author:** [@Pixelaters](https://dragonfly.discourse.group/u/Pixelaters)\ **Replies:** 1\ **Last updated:** [August 30, 2024, 1:53pm UTC](https://dragonfly.discourse.group/t/getting-this-error-failed-to-load-tls-key/207 "2024-08-30T13:53:17Z")
I’m running dragonfly via a docker container and I’m trying to get TLS working. when i run docker compose up I get this error: Failed to load TLS key heres my docker-compose.yaml file version: '3.8' services: dra… --- ## [High CPU Usage When Running As Dockerized Container On Ubuntu 20.04](https://dragonfly.discourse.group/t/high-cpu-usage-when-running-as-dockerized-container-on-ubuntu-20-04/193)
**Author:** [@foxmuldersatya](https://dragonfly.discourse.group/u/foxmuldersatya)\ **Replies:** 7\ **Last updated:** [August 26, 2024, 2:42pm UTC](https://dragonfly.discourse.group/t/high-cpu-usage-when-running-as-dockerized-container-on-ubuntu-20-04/193 "2024-08-26T14:42:14Z")
Hello everyone, I have setup Dragon Fly as a dockerized container which is accessed by a couple of spring boot services. The CPU usage of dragon fly seems to be higher when compared to Redis in idle and under load scenar… --- ## [About the Dragonfly Technical category](https://dragonfly.discourse.group/t/about-the-dragonfly-technical-category/56)
**Author:** [@system](https://dragonfly.discourse.group/u/system)\ **Replies:** 0\ **Last updated:** [May 17, 2024, 5:39pm UTC](https://dragonfly.discourse.group/t/about-the-dragonfly-technical-category/56 "2024-05-17T17:39:12Z")
The Dragonfly Technical category is your hub for troubleshooting, debugging, and in-depth technical discussions related to Dragonfly --- ## [Are replicas read-only (by default)?](https://dragonfly.discourse.group/t/are-replicas-read-only-by-default/156)
**Author:** [@zippy-aardvark](https://dragonfly.discourse.group/u/zippy-aardvark)\ **Replies:** 6\ **Last updated:** [May 9, 2024, 2:24pm UTC](https://dragonfly.discourse.group/t/are-replicas-read-only-by-default/156 "2024-05-09T14:24:12Z")
The docs make no mention of read-only at all (unlike redis) There’s also no mention of the replica-read-only config option on https://www.dragonflydb.io/docs/managing-dragonfly/flags I need writable replicas, so wonder… --- ## [dragonflydb as a service on bare metal (ubuntu 22)](https://dragonfly.discourse.group/t/dragonflydb-as-a-service-on-bare-metal-ubuntu-22/154)
**Author:** [@temperate-seal](https://dragonfly.discourse.group/u/temperate-seal)\ **Replies:** 1\ **Last updated:** [May 7, 2024, 1:03pm UTC](https://dragonfly.discourse.group/t/dragonflydb-as-a-service-on-bare-metal-ubuntu-22/154 "2024-05-07T13:03:33Z")
Hello! Trying to adapt dragonfly for a web application, instead of mysql for caching/sessions… Is there a way to run dragonfly as a service instead of running as a command? I know i can create .service myself, but still,… --- ## [easy installation on Linux and data loss](https://dragonfly.discourse.group/t/easy-installation-on-linux-and-data-loss/155)
**Author:** [@natural-flamingo](https://dragonfly.discourse.group/u/natural-flamingo)\ **Replies:** 2\ **Last updated:** [May 6, 2024, 10:25am UTC](https://dragonfly.discourse.group/t/easy-installation-on-linux-and-data-loss/155 "2024-05-06T10:25:01Z")
Hint, this is a new behavior for me, I’m confused - I probably don’t know something, but more likely I’m lazy and don’t read the manual. Please help me with the section I need to read what do I know about Redis ? I use… --- ## [Renewal authentication key](https://dragonfly.discourse.group/t/renewal-authentication-key/153)
**Author:** [@respectful-baboon](https://dragonfly.discourse.group/u/respectful-baboon)\ **Replies:** 4\ **Last updated:** [April 26, 2024, 11:38pm UTC](https://dragonfly.discourse.group/t/renewal-authentication-key/153 "2024-04-26T23:38:11Z")
Hello everyone, I am in my last year of phd and I have been using Dragonfly, for non profit research. I use it mainly on bacterial cells, seen under confocal microscope with double markers. My one year time has come t… --- ## [Dragonfly keeps asking for authentication](https://dragonfly.discourse.group/t/dragonfly-keeps-asking-for-authentication/151)
**Author:** [@observant-newt](https://dragonfly.discourse.group/u/observant-newt)\ **Replies:** 10\ **Last updated:** [April 16, 2024, 2:44pm UTC](https://dragonfly.discourse.group/t/dragonfly-keeps-asking-for-authentication/151 "2024-04-16T14:44:05Z")
I’m trying to migrate from Redis to Dragonfly. Plan is on only using it for caching. I never used any authentication for Redis, and that worked perfectly. But Dragonfly keeps asking for authentication. --- ## [DB Size of 130k keys but none showing with keys \*](https://dragonfly.discourse.group/t/db-size-of-130k-keys-but-none-showing-with-keys/152)
**Author:** [@munificent-gnu](https://dragonfly.discourse.group/u/munificent-gnu)\ **Replies:** 2\ **Last updated:** [April 14, 2024, 9:20pm UTC](https://dragonfly.discourse.group/t/db-size-of-130k-keys-but-none-showing-with-keys/152 "2024-04-14T21:20:10Z")
Not sure what is happening there, all keys in the db1 are zsets Version: df-v1.16.1 OS: MacOS 14.4.1 (23E224) Image: “docker.dragonflydb.io/dragonflydb/dragonfly” Arguments: - --dbfilename=data - --default\_lua… --- ## [setting up memcached in HA format](https://dragonfly.discourse.group/t/setting-up-memcached-in-ha-format/148)
**Author:** [@zingy-umbrellabird](https://dragonfly.discourse.group/u/zingy-umbrellabird)\ **Replies:** 11\ **Last updated:** [April 9, 2024, 10:21pm UTC](https://dragonfly.discourse.group/t/setting-up-memcached-in-ha-format/148 "2024-04-09T22:21:54Z")
hey all, I was trying to setup memcached in an HA format, ie: with the dragonfly operator sending the requests to underlying dragonflydb instances. I’ve set it up using the kubectl apply commands as seen here: https://… --- ## [Memcached GUI for the whole server or per website?](https://dragonfly.discourse.group/t/memcached-gui-for-the-whole-server-or-per-website/150)
**Author:** [@discrete-yaffle](https://dragonfly.discourse.group/u/discrete-yaffle)\ **Replies:** 8\ **Last updated:** [April 3, 2024, 1:26am UTC](https://dragonfly.discourse.group/t/memcached-gui-for-the-whole-server-or-per-website/150 "2024-04-03T01:26:52Z")
Hello. Just joined, not sure if this the right place for my question. But here is goes… I have just have question because we are looking onto installing memcached on our server: Using a GUI for memcached to manage our… [Next page](https://dragonfly.discourse.group/c/technical/5.md?page=1)