Hi,
Many user are facing email slowness issue, checked and found below alert for all the servers.
Please suggest, what will be the impact of increasing the guard target backend from 150 to 2500 on exchange server and will it resolve the slowness issue?
We have recently changed the activesync from nonsecure (direct connection to Exchange) to secure through Pointsharp (MDM)
Mobiledevice->Load Balancer->5 Exchange server (This was the earlier setup and was working fine)
There are around 5000 users, 5 Mailbox servers, 2 MDM servers
User mailboxes are evenly distributed in all 5 exchange servers MX1,MX2,MX3,MX4,MX5
Mobile device-> 2 MDM servers receiving the request --> sending it to 2 exchange servers MX4, MX5 -> connecting to user mailbox on any of 5 exchange server (This is the change in setup and slowness issue started)
Queue length of MSExchangeSyncAppPool has been changed from 1000 to 2500 on each server after change in setup
Log Name: Application
Source: MSExchange Front End HTTP Proxy
Date: 9/21/2018 10:40:13 AM
Event ID: 2002
Task Category: Core
Level: Warning
Keywords: Classic
User: N/A
Computer: MX5.cryptoso.xyz
Description:
[Eas] The number of outstanding requests for guard TargetBackend("MX1.cryptoso.xyz") has exceeded the max limit 150. Current request will be rejected.
Event Xml:<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event"><System><Provider Name="MSExchange Front End HTTP Proxy" /><EventID Qualifiers="32768">2002</EventID><Level>3</Level><Task>1</Task><Keywords>0x80000000000000</Keywords><TimeCreated SystemTime="2018-09-21T08:40:13.000000000Z" /><EventRecordID>17485533</EventRecordID><Channel>Application</Channel><Computer>MX5.cryptoso.xyz</Computer><Security /></System><EventData><Data>Eas</Data><Data>TargetBackend("MX1.cryptoso.xyz")</Data><Data>150</Data></EventData></Event>Regards, Rahul