# Transactions log errors **URL:** \ **Category:** Server\ **Created:** [July 24, 2024, 8:59am UTC](https://community.neo4j.com/t/transactions-log-errors/68976 "2024-07-24T08:59:57Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![chrszrkl](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/chrszrkl/32/14700_2.png) [@chrszrkl](https://community.neo4j.com/u/chrszrkl)\ **Post date:** [July 24, 2024, 8:59am UTC](https://community.neo4j.com/t/transactions-log-errors/68976/1 "2024-07-24T08:59:57Z")
Hi, I'm running Neo4j v5.17.0 enterprise via Docker and I have CDC enabled. When checking the debug.logs, I find lots of errors like these: ```auto 2024-07-24 08:47:48.527+0000 WARN [o.n.k.i.t.l.f.LogFileChannelNativeAccessor] [db/e570a0d6] Unable to advise sequential access for transaction log version: 0. Error: ErrorCode=-1, errorMessage='Incorrect file descriptor.' 2024-07-24 08:47:48.528+0000 WARN [o.n.k.i.t.l.f.LogFileChannelNativeAccessor] [db/e570a0d6] Unable to advise preserve data in cache for transaction log version: 0. Error: ErrorCode=-1, errorMessage='Incorrect file descriptor.' 2024-07-24 08:47:48.534+0000 WARN [o.n.k.i.t.l.f.c.CheckpointFileChannelNativeAccessor] [db/e570a0d6] Unable to advise sequential access for transaction log version: 0. Error: ErrorCode=-1, errorMessage='Incorrect file descriptor.' 2024-07-24 08:47:48.540+0000 WARN [o.n.k.i.t.l.f.c.CheckpointFileChannelNativeAccessor] [db/e570a0d6] Unable to evict transaction log from cache with version: 0. Error: ErrorCode=-1, errorMessage='Incorrect file descriptor.' ``` I found this article from Neo4j for this one of the errors: [https://support.neo4j.com/s/article/24596542981523-explanation-of-logged-error-Unable-to-advise-sequential-access-for-transaction-log-version-0-Error-ErrorCode-1-errorMessage-Incorrect-file-descriptor](https://support.neo4j.com/s/article/24596542981523-explanation-of-logged-error-Unable-to-advise-sequential-access-for-transaction-log-version-0-Error-ErrorCode-1-errorMessage-Incorrect-file-descriptor) I added the JVM arguments to `neo4j.conf`: ```auto server.jvm.additional=--add-opens=java.base/java.nio=ALL-UNNAMED server.jvm.additional=--add-opens=java.base/java.io=ALL-UNNAMED server.jvm.additional=--add-opens=java.base/sun.nio.ch=ALL-UNNAMED ``` After a restart I can confirm that the arguments were added `VM Arguments`. However, the errors above still occur in the debug logs. ---
**Author:** ![dana\_canzano](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/dana_canzano/32/27392_2.png) [@dana\_canzano](https://community.neo4j.com/u/dana_canzano)\ **Post date:** [July 24, 2024, 2:56pm UTC](https://community.neo4j.com/t/transactions-log-errors/68976/2 "2024-07-24T14:56:21Z")
@chrszrkl Not for nothing but the debug.log lines you reference are `WARN` and not `ERROR`. Is there something else causing you to investigate debug.log lines? ---
**Author:** ![chrszrkl](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/chrszrkl/32/14700_2.png) [@chrszrkl](https://community.neo4j.com/u/chrszrkl)\ **Post date:** [July 24, 2024, 3:32pm UTC](https://community.neo4j.com/t/transactions-log-errors/68976/3 "2024-07-24T15:32:23Z")
Hi @dana_canzano I noticed these are just warnings, but I had some errors for CDC in the debug.log and I think the warnings are somehow related to CDC failing with this error: ```auto 2024-07-24 00:19:01.643+0000 ERROR [c.n.c.CDCService] [db/0a214b04] Unable to create the log scanner for CDC ``` ---
**Author:** ![dana\_canzano](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/dana_canzano/32/27392_2.png) [@dana\_canzano](https://community.neo4j.com/u/dana_canzano)\ **Post date:** [July 24, 2024, 4:08pm UTC](https://community.neo4j.com/t/transactions-log-errors/68976/4 "2024-07-24T16:08:50Z")
@chrszrkl oh. different issue. Are you able to attach the entire logs\debug.log? ---
**Author:** ![dana\_canzano](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/dana_canzano/32/27392_2.png) [@dana\_canzano](https://community.neo4j.com/u/dana_canzano)\ **Post date:** [July 24, 2024, 8:56pm UTC](https://community.neo4j.com/t/transactions-log-errors/68976/5 "2024-07-24T20:56:32Z")
@chrszrkl The error appears to suggest some IOException when reading the txn logs? Are the txn logs present and with expected read/write permissions etc. Anything unusual about the files in data/transactions/db/ But also it appears the database name in question is `db` and but 2 characters. But yet ```auto @neo4j> create database db; Could not create database 'db'. The provided database name must have a length between 3 and 63 characters. @neo4j> ``` or maybe im completely reading this wrong ---
**Author:** ![chrszrkl](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/chrszrkl/32/14700_2.png) [@chrszrkl](https://community.neo4j.com/u/chrszrkl)\ **Post date:** [July 25, 2024, 7:33am UTC](https://community.neo4j.com/t/transactions-log-errors/68976/6 "2024-07-25T07:33:57Z")
Hi @dana_canzano I have shortened the database name in the logs for the sake of brevity - that's why it is only two characters long. The actual database name is `fashionbeauty19qnngn` Here's the full log: > The txn files are readable-writable by user 7474 which should be the Neo4j user from Docker: ```sh root@server:/neo4j/data/transactions/fashionbeauty19qnngn# ls -al total 2280512 drwxr-xr-x 2 7474 7474 4096 Jul 24 13:58 . drwxr-xr-x 19 7474 7474 4096 Jul 23 13:23 .. -rw-r--r-- 1 7474 7474 3840 Jul 25 00:16 checkpoint.0 -rw-r--r-- 1 7474 7474 268734247 Jul 23 15:59 neostore.transaction.db.10 -rw-r--r-- 1 7474 7474 268475789 Jul 23 16:07 neostore.transaction.db.11 -rw-r--r-- 1 7474 7474 269113296 Jul 23 16:16 neostore.transaction.db.12 -rw-r--r-- 1 7474 7474 268646770 Jul 23 16:23 neostore.transaction.db.13 -rw-r--r-- 1 7474 7474 185238660 Jul 25 00:14 neostore.transaction.db.14 -rw-r--r-- 1 7474 7474 268586955 Jul 23 15:26 neostore.transaction.db.6 -rw-r--r-- 1 7474 7474 268608373 Jul 23 15:34 neostore.transaction.db.7 -rw-r--r-- 1 7474 7474 268820285 Jul 23 15:42 neostore.transaction.db.8 -rw-r--r-- 1 7474 7474 268955812 Jul 23 15:50 neostore.transaction.db.9 ``` ---
**Author:** ![dana\_canzano](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/dana_canzano/32/27392_2.png) [@dana\_canzano](https://community.neo4j.com/u/dana_canzano)\ **Post date:** [July 25, 2024, 12:10pm UTC](https://community.neo4j.com/t/transactions-log-errors/68976/7 "2024-07-25T12:10:18Z")
@chrszrkl ah... thanks for this detail that that database name of `db` was not its real name. I regrettably went down a path trying to see if i could get a 2 character database name and maybe somehow this triggered the failure. Was anything else changed? Has CDC ever workded on `db`/ `fashionbeauty19qnngn`? Is this `db` / `fashionbeauty19qnngn` the results of a backup/restore or dump/load ? Have you manipulated any files under data/? ---
**Author:** ![chrszrkl](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/chrszrkl/32/14700_2.png) [@chrszrkl](https://community.neo4j.com/u/chrszrkl)\ **Post date:** [July 25, 2024, 1:15pm UTC](https://community.neo4j.com/t/transactions-log-errors/68976/8 "2024-07-25T13:15:32Z")
Sorry to confuse you with that database name :-D Yes, it usually works without a problem. My assumption is the following: I executed a big transactions with lots of changes that took some time to execute. I think the checkpoint to prune the txn log files every 15 minutes somehow interfered with the running transaction, maybe even corrupting the files. Meanwhile, I added the JVM parameters and increased the allowed log size and duration. It is currently running without issues, so maybe it was related to either the txn log file size or these arguments.