IMAP Tester

imaptest was originally written for stress testing [http://www.dovecot.org/ Dovecot] IMAP server. Its primary testing method is still stress testing, but now it also parses the incoming IMAP replies and complains if anything looks broken.

Compiling

Download and compile Dovecot v1.1 sources. imaptest uses its library functions.
1. Get the latest beta from http://dovecot.org/releases/1.1/beta/
2. Compiling goes the usual way: ./configure && make (there's no need for make install)
Download http://www.dovecot.org/tools/imaptest.c to Dovecot sources' root directory (i.e. where the configure script exists)
imaptest's header comment shows the compile command for gcc, use it or something similar.

You may want to modify the default configuration from #defines at the top of the file. This isn't required, but if you run imaptest often this way you don't have to give the same parameters every time.

Running

The most important parameters (and their defaults) are:

host=127.0.0.1: Host name/IP address where to connect.
port=143: Port what to use.
user=tss: Username template. You can use multiple random users and domains by giving %d in the template. So for example user%d returns user1..user100 and user%d@domain%d.org returns user1..100@domain1..100.org. The 1..100 range is hardcoded to the binary. You can change them from USER_RAND and DOMAIN_RAND defines.
password=pass: Password to use for all users. There's currently no way to use different passwords for different users.
mbox=/home/tss/mail/dovecot-crlf: Path to mbox file where to append messages from. See below for how this is used.

Other useful parameters include:

clients=10: Number of simultaneous client connections to use.
secs=n: Run imaptest n seconds and then exit.
box=INBOX: Mailbox to use for testing. INBOX is the default.
copybox=n: When testing COPY command, this specifies the destination mailbox.
seed=n: Seed to use for random generator. Setting this to some specific value makes repeated benchmarks a bit more reliable, because the used commands should be the same then.
disconnect_quit: If a client gets disconnected, quit. Use logout=0 parameter with this one. This is useful when debugging some problem in the server.
no_pipelining: Don't send multiple commands at once to server.

Selecting what to test:

<state>=<probability>[,<probability2>]: State probabilities to use. See below.
checkpoint=n: Run a checkpoint every n seconds. See below.
random: Switch randomly between states.
no_tracking: Don't track and complain about IMAP state. Makes it use a bit less CPU.

Append mbox

When saving messages, imaptest needs to get the messages from somewhere. mbox=path parameter specifies path to a file in mbox format that's used. Messages are sequentially appended from there. Once imaptest reaches the last message, it wraps back to appending the first message.

Currently imaptest's state tracking expects that Message-IDs are unique within the mbox, otherwise it gives bogus errors. If you really want to avoid changing the Message-IDs, use no_tracking setting to disable state tracking.

You can get a test mbox file from for example http://dovecot.org/archives/dovecot.mbox. Note that it contains non-unique Message-IDs so you'll have to write some script to change those.

States

Name	Short name	Description
AUTHENTICATE	Auth
LOGIN	Logi
LIST	List
LCREATE	LCre
LDELETE	LDel
STATUS	Stat
SELECT	Sele
FETCH	Fetc
FETCH2	Fet2
SEARCH	Sear
SORT	Sort
THREAD	Thre
COPY	Copy
STORE	Stor
DELETE	Dele
EXPUNGE	Expu
APPEND	Appe
NOOP	Noop
CHECK	Chec
LOGOUT	Logo
DISCONNECT	Disc
DELAY	Dela
CHECKPOINT!	ChkP

State tracking

imaptest should catch the following errors:

Referring to sequences that haven't been announced with EXISTS.
Sequence <-> UID map changes unexpectedly
Message's metadata changes unexpectedly. Messages are uniquely identified by their Message-ID: header.
- BODY, BODYSTRUCTURE, ENVELOPE and RFC822.SIZE are currently tracked.
- IMAP servers handle FETCHes for expunged messages differently. imaptest tries to catch these.
FETCH FLAGS listing keywords that haven't been announced with untagged FLAGS.
Untagged FLAGS reply dropping a keyword that's still in use.

Checkpointing works by letting all the pending commands finish. Then CHECK command is sent to all sessions. Once they're done, imaptest verifies that all clients' mailbox state looks exactly the same: