Why is my WebApp only allowed to make 128 connections to an Oracle Database

Matthew Norman 20 Reputation points

we have a (slotted) web app that makes connections (via hcm/relay) to an on prem Oracle database. we were asked to put a scheduled flush of the app service (a pipeline containing only a 'Stop Azure App Service' followed by a 'Start Azure App Service' task against the existing production slot only) which now runs weekly. However since the first run , app insights is reporting Oracle.ManagedDataAccess.Client.OracleException at OracleInternal.ConnectionPool.PoolManager errors once the relay is reporting 128 Active Connections. Prior to running this pipeline we were able to get to roughly 1500 connections before seeing any issues, but now it seems like a hard 128 limit. Nothing else has changed other than the stop/start pipeline being run.

Azure App Service
Azure App Service
Azure App Service is a service used to create and deploy scalable, mission-critical web apps.
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  1. brtrach-MSFT 12,266 Reputation points Microsoft Employee

    @Matthew Norman This does not initially appear to be a limitation of the Azure App Service platform, which I am most knowledgeable to speak on. My belief for this reasoning is that the number of connections allowed is normally in the 1,000s depending on the size of your instance.

    This is likely a limitation within Oracle that you are hitting. From my research, Oracle seems to impose a limit of around 100 connections. You can increase the limit as described here: https://docs.oracle.com/en/database/oracle/oracle-database/21/jjucp/controlling-pool-size.html#GUID-1909EBD1-E526-4385-9A2A-39C89F985A14

    How high you set the limit is ultimately up to you and the strength of your Oracle server. It's also recommended that you ensure your code is optimized to close connections when it is finished with them.

    Again, please keep in mind that I am not an Oracle specialist, but I hope this helps get you pointed the right direction. Reply back to this answer if I can assist you further.