[imp] New IMAP server, troubleshooting slow IMP performance

[Simon Wilson]

I've just moved over to a new IMAP server on my local network,  
migrating IMAP from a CentOS 5 to a CentOS 7 server in the process.  
Horde/apache are on a separate server on the same network as both the  
old and new IMAP servers.

I'm trying to troubleshoot laggy performance in Imp since the move.

For example, refreshing the mail list in Inbox and deleting an email  
each take 3 to 4 seconds before the Refresh circle stops spinning and  
the list is updated. This is longer than it was before (1 to 2 seconds  
typically). It just means that overall Imp feels very slow.

I enabled debug in Imp's config, and the comms with the server appear  
fast - a total transaction time for this set of 0.1683 seconds (see  
below).

Any pointers on why Imp would be slow in this scenario, and what I can  
do to troubleshoot?

Simon



------------------------------
>> Wed, 26 Jul 2017 11:51:23 +1000
>> Connection to: imap://emp07.simonandkate.lan/
>> Server connection took 0.0217 seconds.
S: * OK [CAPABILITY IMAP4rev1 LITERAL+ ID ENABLE STARTTLS  
LOGINDISABLED] emp07 Cyrus IMAP v2.4.17-Fedora-RPM-2.4.17-8.el7_3.1  
server ready
C: 1 STARTTLS
S: 1 OK Begin TLS negotiation now
>> Command 1 took 0.0112 seconds.
>> Successfully completed TLS negotiation.
C: 2 CAPABILITY
S: * CAPABILITY IMAP4rev1 LITERAL+ ID ENABLE ACL RIGHTS=kxte QUOTA  
MAILBOX-REFERRALS NAMESPACE UIDPLUS NO_ATOMIC_RENAME UNSELECT CHILDREN  
MULTIAPPEND BINARY CATENATE CONDSTORE ESEARCH SORT SORT=MODSEQ  
SORT=DISPLAY THREAD=ORDEREDSUBJECT THREAD=REFERENCES ANNOTATEMORE  
LIST-EXTENDED WITHIN QRESYNC SCAN XLIST URLAUTH URLAUTH=BINARY  
X-NETSCAPE AUTH=PLAIN AUTH=LOGIN SASL-IR COMPRESS=DEFLATE IDLE
S: 2 OK Completed
>> Command 2 took 0.0014 seconds.
C: 3 AUTHENTICATE PLAIN [INITIAL CLIENT RESPONSE (username: simon)]
S: 3 OK [CAPABILITY IMAP4rev1 LITERAL+ ID ENABLE ACL RIGHTS=kxte QUOTA  
MAILBOX-REFERRALS NAMESPACE UIDPLUS NO_ATOMIC_RENAME UNSELECT CHILDREN  
MULTIAPPEND BINARY CATENATE CONDSTORE ESEARCH SORT SORT=MODSEQ  
SORT=DISPLAY THREAD=ORDEREDSUBJECT THREAD=REFERENCES ANNOTATEMORE  
LIST-EXTENDED WITHIN QRESYNC SCAN XLIST URLAUTH URLAUTH=BINARY  
X-NETSCAPE LOGINDISABLED COMPRESS=DEFLATE IDLE] Success (tls  
protection) SESSIONID=<emp07-12494-1501033884-1>
>> Command 3 took 0.0134 seconds.
>> CACHE: Using the IMP_Imap_Cache_Wrapper storage driver.
C: 4 ENABLE QRESYNC
C: 5 NAMESPACE
S: * ENABLED CONDSTORE QRESYNC
S: 4 OK Completed
>> Command 4 took 0.0116 seconds.
S: * NAMESPACE (("INBOX/" "/")) (("user/" "/")) (("" "/"))
S: 5 OK Completed
>> Command 5 took 0.0127 seconds.
C: 6 LIST () "" (INBOX INBOX/* user/* *) RETURN (SUBSCRIBED)
S: * LIST (\Subscribed \HasChildren) "/" INBOX (CHILDINFO (SUBSCRIBED))

<<snip a whole lot of folders repeated several times, but which don't  
appear to take long >>

S: * LIST () "/" user/server/Trash
S: 6 OK Completed (0.020 secs 1036 calls)
>> Command 6 took 0.0473 seconds.
C: 7 LIST () "" (INBOX INBOX/* user/* *) RETURN (SUBSCRIBED)
S: * LIST (\Subscribed \HasChildren) "/" INBOX (CHILDINFO (SUBSCRIBED))

<< and again >>

S: * LIST () "/" user/server/Trash
S: 7 OK Completed (0.020 secs 1036 calls)
>> Command 7 took 0.0463 seconds.
C: 8 STATUS INBOX (MESSAGES UIDNEXT HIGHESTMODSEQ)
S: * STATUS INBOX (MESSAGES 33 UIDNEXT 135065 HIGHESTMODSEQ 183)
S: 8 OK Completed
>> Command 8 took 0.001 seconds.
C: 9 STATUS INBOX/Sent (MESSAGES UIDNEXT HIGHESTMODSEQ)
S: * STATUS INBOX/Sent (MESSAGES 9827 UIDNEXT 9975 HIGHESTMODSEQ 4)
S: 9 OK Completed
>> Command 9 took 0.001 seconds.
C: 10 LOGOUT
S: * BYE LOGOUT received
S: 10 OK Completed
>> Command 10 took 0.0007 seconds.

-- 
Simon Wilson
M: 0400 12 11 16