fail upload file more 600 mb to chat - access token is not valid

[progserega]

Description

upload file over 600 mb fail at end of upload process. In encrypted or not room.

Steps to reproduce

1. setup synapse by https://github.com/spantaleev/matrix-docker-ansible-deploy
2. set params (and check in config of synapse):

max_upload_size: 3000M
caches:
  cache_autotuning:
    max_cache_memory_usage: 2095841280
    min_cache_ttl: 30s
    target_cache_memory_usage: 1047920640
  cache_entry_ttl: 1080m
  expire_caches: true
  global_factor: 10
  per_cache_factors: null
  sync_response_cache_duration: 2m

1. create user
2. connect from firefox element-web to matrix-server
3. create encrypted and not encrypted room
4. try send big files (600 mb and 1,8 Gb) to this rooms
5. 600 mb send success
6. 1,8 Gb - wait, when file fully upload ~3 minutes (in UI of element-web) - after that element show dialog, that upload is failed.

Homeserver

test-matrix.ru

Synapse Version

1.147.1

Installation Method

Other (please mention below)

Database

single PostgreSQL in docker

Workers

Single process

Platform

https://github.com/spantaleev/matrix-docker-ansible-deploy

Configuration

presence:
enabled: true
retention: null
modules: []

Relevant log output

Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,517 - synapse.access.http.8008 - 596 - DEBUG - POST-330 - 217.150.78.4 - 8008 - Received request: POST /_matrix/media/v3/upload?filename=proxmox-ve_9.1-1.iso
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,517 - synapse.api.auth.mas - 226 - DEBUG - POST-330 - Fetching token from MAS
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-authentication-service[31823]: 2026-02-20T14:14:05.518727Z  WARN mas_handlers::oauth2::introspection:134 POST-1290 -

[synapse.log](https://github.com/user-attachments/files/25444730/synapse.log)

Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-authentication-service[31823]: 2026-02-20T14:14:05.518760Z  INFO http.server.response POST-1290 - "POST /oauth2/introspect HTTP/1.1" 200 OK "Synapse/1.147.1" [polls: 4, cpu: 0.2ms, elapsed: 0.7ms]
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,519 - synapse.api.auth.mas - 250 - DEBUG - POST-330 - Fetched token from MAS
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,519 - synapse.api.auth.mas - 329 - DEBUG - POST-330 - Introspection result: IntrospectionResponse(retrieved_at_ms=1771596845519, active=False, scope=None, username=None, sub=None, device_id=None, expires_in=None)
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,519 - synapse.http.server - 131 - INFO - POST-330 - <XForwardedForRequest at 0x7f6c1479a0d0 method='POST' uri='/_matrix/media/v3/upload?filename=proxmox-ve_9.1-1.iso' clientproto='HTTP/1.1' site='8008'> SynapseError: 401 - Token is not active
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,661 - synapse.access.http.8008 - 641 - INFO - POST-330 - 217.150.78.4 - 8008 - {None} Processed request: 0.002sec/0.000sec (0.000sec, 0.140sec) (0.000sec/0.000sec/0) 79B 401 "POST /_matrix/media/v3/upload?filename=proxmox-ve_9.1-1.iso HTTP/1.1" "Mozilla/5.0 (X11; Linux x86_64; rv:140.0) Gecko/20100101 Firefox/140.0" [0 dbevts]
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,662 - synapse.handlers.sync - 1668 - DEBUG - GET-478 - Calculating sync response for @denshark:test-matrix.ru between StreamToken(room: RoomStreamToken(stream: 119, topological: None, instances: {}), presence: 5004, typing: 0, receipt: MultiWriterStreamToken(stream: 64, instances: {}), account_data: 128, push_rules: 1, to_device: 24, device_list: MultiWriterStreamToken(stream: 97, instances: {}), groups: 0, un_partial_stated_rooms: 1,thread_subscriptions: 2) and StreamToken(room: RoomStreamToken(stream: 119, topological: None, instances: {}), presence: 5006, typing: 0, receipt: MultiWriterStreamToken(stream: 64, instances: {}), account_data: 128, push_rules: 1, to_device: 24, device_list: MultiWriterStreamToken(stream: 97, instances: {}), groups: 0, un_partial_stated_rooms: 1,thread_subscriptions: 2)
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,662 - synapse.handlers.sync - 1675 - DEBUG - GET-478 - Fetching account data
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,662 - synapse.handlers.sync - 1698 - DEBUG - GET-478 - Fetching room data
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,662 - synapse.util.metrics - 239 - DEBUG - GET-478 - Entering block ephemeral_by_room
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,662 - synapse.util.metrics - 239 - DEBUG - GET-478 - Entering block typing.get_new_events
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,662 - synapse.util.metrics - 252 - DEBUG - GET-478 - Exiting block typing.get_new_events
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,663 - synapse.util.metrics - 252 - DEBUG - GET-478 - Exiting block ephemeral_by_room
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,663 - synapse.handlers.sync - 2177 - DEBUG - GET-478 - no-oping sync
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,663 - synapse.handlers.sync - 1721 - DEBUG - GET-478 - Fetching presence data
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,663 - synapse.util.metrics - 239 - DEBUG - GET-478 - Entering block presence.get_new_events
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,663 - synapse.util.metrics - 252 - DEBUG - GET-478 - Exiting block presence.get_new_events
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,663 - synapse.handlers.sync - 1744 - DEBUG - GET-478 - Fetching to-device data
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,663 - synapse.handlers.sync - 1747 - DEBUG - GET-478 - Fetching OTK data
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,663 - synapse.handlers.sync - 1776 - DEBUG - GET-478 - Sync response calculation complete
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,664 - synapse.handlers.sync - 367 - DEBUG - GET-478 - Returning sync response for @denshark:test-matrix.ru
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,664 - synapse.rest.client.sync - 303 - DEBUG - GET-478 - Formatting events in sync response
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,664 - synapse.rest.client.sync - 338 - DEBUG - GET-478 - building sync response dict
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,664 - synapse.rest.client.sync - 291 - DEBUG - GET-478 - Event formatting complete
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-traefik[31981]: 217.150.78.4 - - [20/Feb/2026:14:07:36 +0000] "POST /_matrix/media/v3/upload?filename=proxmox-ve_9.1-1.iso HTTP/3.0" 401 95 "-" "-" 256 "matrix-synapse-public-client-api@docker" "http://172.23.0.8:8008" 388683ms
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,665 - synapse.access.http.8008 - 641 - INFO - GET-478 - 2.63.234.138 - 8008 - {@denshark:test-matrix.ru} Processed request: 30.073sec/0.001sec (0.002sec, 0.004sec) (0.000sec/0.001sec/1) 440B 200 "GET /_matrix/client/v3/sync?filter=0&timeout=30000&org.matrix.msc4222.use_state_after=true&set_presence=unavailable&since=s119_5004_0_64_128_1_24_97_0_1_2 HTTP/1.1" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36" [0 dbevts]
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-traefik[31981]: 2.63.234.138 - - [20/Feb/2026:14:13:35 +0000] "GET /_matrix/client/v3/sync?filter=0&timeout=30000&org.matrix.msc4222.use_state_after=true&set_presence=unavailable&since=s119_5004_0_64_128_1_24_97_0_1_2 HTTP/3.0" 200 258 "-" "-" 339 "matrix-synapse-public-client-api@docker" "http://172.23.0.8:8008" 30075ms
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,769 - synapse.access.http.8008 - 596 - DEBUG - OPTIONS-487 - 2.63.234.138 - 8008 - Received request: OPTIONS /_matrix/client/v3/sync?filter=0&timeout=30000&org.matrix.msc4222.use_state_after=true&set_presence=unavailable&since=s119_5006_0_64_128_1_24_97_0_1_2
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,770 - synapse.access.http.8008 - 641 - DEBUG - OPTIONS-487 - 2.63.234.138 - 8008 - {None} Processed request: 0.000sec/-0.000sec (0.000sec, 0.000sec) (0.000sec/0.000sec/0) 0B 204 "OPTIONS /_matrix/client/v3/sync?filter=0&timeout=30000&org.matrix.msc4222.use_state_after=true&set_presence=unavailable&since=s119_5006_0_64_128_1_24_97_0_1_2 HTTP/1.1" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36" [0 dbevts]
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-traefik[31981]: 2.63.234.138 - - [20/Feb/2026:14:14:05 +0000] "OPTIONS /_matrix/client/v3/sync?filter=0&timeout=30000&org.matrix.msc4222.use_state_after=true&set_presence=unavailable&since=s119_5006_0_64_128_1_24_97_0_1_2 HTTP/3.0" 204 0 "-" "-" 342 "matrix-synapse-public-client-api@docker" "http://172.23.0.8:8008" 1ms
Feb 20 14:14:05 compute-vm-2-2-30-hdd-1736421736624 matrix-synapse[32258]: 2026-02-20 14:14:05,805 - synapse.handlers.sync - 1668 - DEBUG - GET-480 - Calculating sync response for @test2:test-matrix.ru between StreamToken(room: RoomStreamToken(stream: 119, topological: None, instances: {}), presence: 5004, typing: 0, receipt: MultiWriterStreamToken(stream: 64, instances: {}), account_data: 128, push_rules: 1, to_device: 24, device_list: MultiWriterStreamToken(stream: 97, instances: {}), groups: 0, un_partial_stated_rooms: 1,thread_subscriptions: 2) and StreamToken(room: RoomStreamToken(stream: 119, topological: None, instances: {}), presence: 5006, typing: 0, receipt: MultiWriterStreamToken(stream: 64, instances: {}), account_data: 128, push_rules: 1, to_device: 24, device_list: MultiWriterStreamToken(stream: 97, instances: {}), groups: 0, un_partial_stated_rooms: 1,thread_subscriptions: 2)

Anything else that would be useful to know?

No response

[YamatoRyou]

#13009

I'm not part of the development team, but I can offer some observations:

1. The larger the file, the higher the upload failure rate. This can be due to two scenarios:
   a) The write time is too long (depending on both hard drive performance and Synapse's write strategy). If Synapse fails to complete the write within 30 seconds, the client will actively interrupt the upload;
   b) The upload coincides with an access token change, causing the token carried in the upload request to become invalid, thus leading to upload failure.
2. Synapse theoretically only supports a maximum single file upload size of 1.999999 GB (depending on the database design), so specifying 3000 MB in the configuration file is meaningless.

[progserega]

@YamatoRyou do you try fix this bug by strategy:

1. alter table local_media_repository for change media_length from integer to bigint
2. fix SDK of clients to change timeout from 30 seconds to 30 minutes: https://github.com/matrix-org/matrix-js-sdk/blob/12253064d14b6a3f3b043cf3bdd382d520d0c13b/src/http-api.ts#L419-L423
3. fgrep all string media_length in synapse source and check, that it will be correct work (with new type of column).

For prodaction use, when we try migrate from telegram - this limitation is very serious.

[YamatoRyou]

@YamatoRyou do you try fix this bug by strategy:

1. alter table local_media_repository for change media_length from integer to bigint
2. fix SDK of clients to change timeout from 30 seconds to 30 minutes: https://github.com/matrix-org/matrix-js-sdk/blob/12253064d14b6a3f3b043cf3bdd382d520d0c13b/src/http-api.ts#L419-L423
3. fgrep all string media_length in synapse source and check, that it will be correct work (with new type of column).

For prodaction use, when we try migrate from telegram - this limitation is very serious.

I tried the first option but ultimately abandoned it. Given that my server is already in use, I'm unsure if it might introduce any unforeseen risks.
I haven't tried the second and third options, and they seem impractical (requiring significant additional maintenance) and could potentially be problematic.

Since this issue remains unresolved, my final solution is: for large file transfer scenarios, use a self-hosted external service (such as PsiTransfer).

[progserega]

I continue testing this bug...
I test upload 600 Mb file on server matrix-synapse version 1.134.0 without MAS, but with nginx. I incress max upload size in synapse:

max_upload_size: 2000M

and in nginx:

      client_max_body_size    800M;
      client_body_buffer_size 1280k;

So after that - I success upload file 627519488 bytes (599M) to this server.

In previouse tests (upload to matrix-synapse server with configured MAS) - this file was not upload to server never.

[progserega]

Also we try enable workers. Theoretically this can help parallelize processing requests and workaround token timeout. But this was not help.

I think problem occurs between MAS and matrix-synapse. SSO add this bug.

[progserega]

I setup matrix over https://github.com/spantaleev/matrix-docker-ansible-deploy - so there are use traefik as proxy. Nginx not supported. So, when add middleware

traefik.http.middlewares.buffer-large-uploads.buffering.maxRequestBodyBytes=1273741824
traefik.http.middlewares.buffer-large-uploads.buffering.memRequestBodyBytes=2097152

and

traefik.http.routers.matrix-synapse-public-client-root.middlewares=buffer-large-uploads,compression@file,matrix-synapse-public-client-root-redirect

• I can upload 950 Mb file to matrix with MAS enabled.

This options - enable local buffering in http-proxy (traefik), so all data go to matrix synapse momentously, whithout big timeout for uploading. This timeouts get http-proxy (traefik) when download data from client, then all data send to matrix-synapse from own buffer..