1 © 2003, Cisco Systems, Inc. All rights reserved. Proprietary and Confidential Unity Connection...

1© 2003, Cisco Systems, Inc. All rights reserved. Proprietary and Confidential

Unity Connection 7.0(1)Messaging Redundancy

TOIJuly 2008

Jane Rygg

[email protected]

222© 2003, Cisco Systems, Inc. All rights reserved. Proprietary and ConfidentialPresentation_ID

Overview

• Server Roles

• Split Brain

• System Maintenance

• Troubleshooting


Server Roles

• Primary

Message store database access

MTA

Notifier

• Secondary

Warm copy of message store database

• Both servers

Message store attachment access (file system)

UMSS IMAP Server

SMTP Server


Primary Server

File Store

IDS Server

Access UMSS

DirectoryStore

MessageHeader

Message Submission &

Retrieval

Subscriber Messages

CML

Access Attachments

Access MessageHeaders

JNI


Retrieval

MessageAttachments

UMSS

Primary

IMAP Server


`

IMAP/SMTP Client

Access Messages

VPIM Server

VPIMMessages

SMTP

SERVER

Incoming SMTP

Messages

CsMalUmssCsMalIMAP

MicrosoftExchange

Server

UMSS access

MTA

Outgoing VPIM

messages

Corporate Fire Wall

Remote SMTP

Servers

Corporate SMTPServerSMTP

Communication

Outgoing Notification messages

AccessText

Messages

TTS Text messages

Tomcat

Access Attachments

CPCA Client

Notifier

CsMALUmss

SMTP NotificationMessages

MessageNotification

CDE (TUI)

Message Record &

Play

User

Message Record &

Play

Ex-Drop Folder

Drop Folder

SMTPPickup

Outgoing VPIM

messages

Remote SMTP

Servers

Secondary

SMTPMessages

SMTPMessages

CuFileSync

Drop Folder Files

Message Attachments Message

Attachments

IncomingSMTP

Message

SubscriberMessage


Secondary Server

File Store


Retrieval

Subscriber Messages

CML

Access Attachments


JNI


Retrieval

UMSS

Secondary

IMAP Server


`

IMAP/SMTP Client

Access Messages

VPIM Server

VPIMMessages

SMTP

SERVER

Incoming SMTP

Messages

CsMalUmssCsMalIMAP

MicrosoftExchange

Server

UMSS access

Corporate Fire Wall

Remote SMTP

Servers

Corporate SMTPServerSMTP

Communication

Outgoing Notification messages

AccessText

Messages

TTS Text messages

Tomcat

Access Attachments

CPCA Client

CDE (TUI)

Message Record &

Play

User

Message Record &

Play

Ex-Drop Folder

Drop Folder

Outgoing VPIM

messages

Remote SMTP

Servers

Primary

CuFileSyncSubscriber Messages Incoming SMTP Messages

Drop Folder Files

Message Attachments

Message Attachments

SMTP Messages

SMTP Messages


Message Flow - Delivery

Caller CsMal MTA UMSS Database File System

Gather recipients, recording, and message info from sender

Create draft message

Submit draft message

Wait for messages in MTA drop folder

Message into MTA drop

Submit complete

Pull message from queue and parses

message

Store message parts as files

Store headers in db

Caller on Secondary Leaves A Message

CuFileSync

Move to Primary MTA Drop

Queue for Replication

File System UMSS Database

Copy Attachments to Secondary

Database Replication

Primary ServerSecondary Server

CuFileSync


SMTP Notification

• Notifications sent from server with primary role.

• Link to PCA in SMTP notification messages will default to the server hostname which sends the notification.

• Address to use in the PCA link can be configured on CUCA, Advanced Settings, Connection Administration: Host Name/Address for Link to Cisco PCA in Notification Messages


Split Brain

• Split Brain occurs when connectivity between the servers is lost and both become primary

• Changes to the message store (database and attachments in the file system) queue up

• Messages are stamped with identifiers called UIDs. Each message in a mailbox has a UID unique to the mailbox.

• During Split Brain, the servers may create messages with the same UIDs.


Split Brain Recovery

• Split Brain Resolution occurs when the servers reconnect.

• The databases are reconciled with last write win.

• A script is called to renumber messages those messages that arrived during Split Brain so that message UIDs are again unique within the mailbox.

• If Split Brain continues for a while, it could happen that the changes during Split Brain are too many to be queued and in this situation messages can be lost.


System Maintenance

• Multiple Mail Stores

• UMSS Tasks


Multiple Mail Stores

• Up to 5 may be created

• UnityMbxDb1 is default

• Create/delete from publisher (1st node in cluster)

• Move mailboxes between mail stores on either publisher or subscriber


Mailbox Store Size(s)

• Mail store attachment size should be the same on the servers

• The current size shown on the Mailbox Store page is the size of the attachments on the disk on the primary.

• The Monitor Disk Space Task on each server will report disk usage for each mailbox store.

• A discrepancy in disk usage between the servers may indicate a file sync problem


UMSS Tasks that run on Primary only

Message Aging Based on message aging rules, cleans expired messages from the mailbox of the Unity Subscriber. Does not delete associated audio file(s).

Clean Deleted Messages This task deletes messages from Unity databases and the file system which are marked to have no recipients

Clean Lost Deleted Messages

This task deletes messages from Unity databases and the file system which have no recipients. More thorough than the task above but run less often for performance reasons.

Monitor System Mailboxes

Monitors the system mailboxes and reports the number of messages per mailbox.

Clean Orphaned Messages

Cleans orphaned messages from the Unity database and the file system.

Note: Rare and unexpected error case


UMSS Tasks that run on both servers

Monitor Bad Mail Monitors the MTA bad mail and STMP bad mail folders, which may contain messages that could not be delivered or NDRed, and reports the number of

messages. Clean Orphaned Message Stream Files

Cleans orphaned message stream files from the file system.

Note: Rare and unexpected error case

Purge Empty Message Stream File Directories

Removes directories from which all message stream files have been deleted

Monitor Disk Space Monitors Unity System disk usage and sends alerts if disk volume is getting full or mail stores approaching specified max size.

Refresh Mail Store Sizes Refreshes cached mail store attachment size. Background task for performance reasons.


Troubleshooting

• File replication service not running

1 © 2003, Cisco Systems, Inc. All rights reserved. Proprietary and Confidential Unity Connection...

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