# Db migration is failing for large tables : Cassandra to MySQL

**URL:** <https://community.cdata.com/t/db-migration-is-failing-for-large-tables-cassandra-to-mysql/607>\
**Category:** CData Connect Cloud\
**Tags:** question, mysql, cdata-sync, cassandra\
**Created:** [January 25, 2024, 6:34am UTC](https://community.cdata.com/t/db-migration-is-failing-for-large-tables-cassandra-to-mysql/607 "2024-01-25T06:34:57Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![db\_maverick](https://avatars.discourse-cdn.com/v4/letter/d/9fc348/32.png) [@db\_maverick](https://community.cdata.com/u/db_maverick)\
**Post date:** [January 25, 2024, 6:35am UTC](https://community.cdata.com/t/db-migration-is-failing-for-large-tables-cassandra-to-mysql/607/1 "2024-01-25T06:35:28Z")

</div>

Hi,

I have been trying to migrate data from cassandra to mysql..The size of the source data table is approx. 4.5 GB.  
The migration job ran for 11 hours and then failed with below error:

2024-01-24T22:13:40.908+0530&nbsp;&nbsp; &nbsp;1&nbsp;&nbsp; &nbsp;[2|Q-Id]&nbsp;&nbsp; &nbsp;[SQL |Cache] The operation timed out.  
2024-01-24T22:13:40.955+0530&nbsp;&nbsp; &nbsp;1&nbsp;&nbsp; &nbsp;[2|Q-Id]&nbsp;&nbsp; &nbsp;[SQL |Cache] Cache failed: The operation timed out.  
2024-01-24T22:13:40.955+0530&nbsp;&nbsp; &nbsp;0&nbsp;&nbsp; &nbsp;[2|Q-Id]&nbsp;&nbsp; &nbsp;[SQL |Cache] Replication Failed. Error:The operation timed out.  
2024-01-24T22:13:40.955+0530&nbsp;&nbsp; &nbsp;1&nbsp;&nbsp; &nbsp;[2|Q-Id]&nbsp;&nbsp; &nbsp;[RealDB:cdata.jdbc.cassandra.CassandraDriver]The connection is disconnected.  
2024-01-24T22:13:40.955+0530&nbsp;&nbsp; &nbsp;1&nbsp;&nbsp; &nbsp;[2|Q-Id]&nbsp;&nbsp; &nbsp;[RealDB:MySQL]The connection is disconnected.  
2024-01-24T22:13:40.955+0530&nbsp;&nbsp; &nbsp;1&nbsp;&nbsp; &nbsp;[2|Q-Id]&nbsp;&nbsp; &nbsp;[RealDB:Derby]The connection is disconnected.  
2024-01-24T22:13:40.955+0530&nbsp;&nbsp; &nbsp;1&nbsp;&nbsp; &nbsp;[2|Q-Id]&nbsp;&nbsp; &nbsp;[SQL |Messag] Query Failed: [REPLICATE [orderdashboard] WITH \_id = ‘dVliqUz79KW/pJr8i8+vNg==’, ReplicateID = ‘ym5RUxyrxDweS3YeOqwAow==’ SELECT \* FROM [hendrixstg\_bkp].[orderdashboard]]. Error: The operation timed out.  
2024-01-24T22:13:40.955+0530&nbsp;&nbsp; &nbsp;2&nbsp;&nbsp; &nbsp;[|Q-Id]&nbsp;&nbsp; &nbsp;The operation timed out.  
XcoreXreplicateX230X8698.dce  
&nbsp;&nbsp; &nbsp;at XcoreXmysqlX230X8771.aic.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXmysqlX230X8771.aic.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXmysqlX230X8771.yhc.execute(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.cjd.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.cjd.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.thd.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.tjd.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.tjd.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.yid.b(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.yid.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.cjd.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.thd.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.zrb.H(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.zrb.b(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.pqb.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.hqe.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.oqe$f.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.oqe$f.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.oqe$g.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.oqe.b(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.oqe.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.cyc.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.cyc.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.vib.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.dvb.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.had.E(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.upc.b(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.pqb.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.ofc.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.ofc.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXreplicateX230X8698.ofc.executeUpdate(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXcdata.syncX233X8700.ngb.c(Unknown Source)  
&nbsp;&nbsp; &nbsp;at rssbus.syncops.CallStackKeeper.executeSyncUpdate(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXcdata.syncX233X8700.yeb.run(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXcdata.syncX233X8700.web.a(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXcdata.syncX233X8700.xeb.executeQueries(Unknown Source)  
&nbsp;&nbsp; &nbsp;at XcoreXcdata.syncX233X8700.xeb.runImpl(Unknown Source)  
&nbsp;&nbsp; &nbsp;at rssbus.syncops.JobExecContext.run(Unknown Source)  
&nbsp;&nbsp; &nbsp;at java.base/java.lang.Thread.run(Unknown Source)  
2024-01-24T22:13:40.976+0530&nbsp;&nbsp; &nbsp;1&nbsp;&nbsp; &nbsp;[2|Q-Id]&nbsp;&nbsp; &nbsp;[INFO|Connec] Closed Replicate connection

Can someone please help with this?

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<div class="post-metadata">

**Author:** ![anonymous](https://avatars.discourse-cdn.com/v4/letter/a/8491ac/32.png) [@anonymous](https://community.cdata.com/u/anonymous)\
**Post date:** [February 1, 2024, 3:50pm UTC](https://community.cdata.com/t/db-migration-is-failing-for-large-tables-cassandra-to-mysql/607/2 "2024-02-01T15:50:56Z")

</div>

Hello! I’m sorry to hear about this issue you’re facing with CData Sync. In order to properly determine the cause behind a timeout error like this, logging information will likely be necessary.

Something like that would best be suited for our dedicated technical support team though. I’d highly recommend reaching out to them at&nbsp;[support@cdata.com](mailto:support@cdata.com)&nbsp;with additional information regarding the issue you’re experiencing.

Once they get back to you, they can share all the steps you need in order to generate some logging information that will help them resolve this issue.