Informix Error -44

Important platform note. Error codes in this range represent operating-system errno values whose meanings vary between Unix platforms and versions. Confirm the native errno definition on the server where the Informix error occurred before diagnosing the problem from the number alone.

Determine the Native Error Meaning

	Value	Symbol
Catalogue text — Socket type not supported	44	ESOCKTNOSUPPORT on BSD
The same condition on Linux	94	ESOCKTNOSUPPORT
Errno 44 on Linux	44	ECHRNG — Channel number out of range, STREAMS-era

Codes -42 to -55 are the BSD socket block and each sits 50 higher on Linux.

python3 -c 'import os; print(44, os.strerror(44)); print(94, os.strerror(94))'

What ESOCKTNOSUPPORT Actually Tells You

The socket type — SOCK_STREAM, SOCK_DGRAM, SOCK_RAW, SOCK_SEQPACKET — is not supported for the family and protocol requested.

It is the rarest of the four creation-time refusals, because the common combinations are universally supported. A stream socket over TCP works everywhere; you have to ask for something unusual to be refused.

Error	Symbol	What was refused
-43	EPROTONOSUPPORT	The protocol
-44	ESOCKTNOSUPPORT	The socket type
-46	EPFNOSUPPORT	The protocol family
-47	EAFNOSUPPORT	The address family

All four are decided at socket(), and stacks report them somewhat interchangeably. Which of the four you receive says more about the implementation than about the mistake.

What This Means in Informix

The engine's normal connection handling will not produce this. Informix's network protocols use ordinary stream sockets, which every supported platform provides.

A -44 therefore points at something around the instance rather than at it:

• Custom code opening its own socket — a C UDR, a wrapper, a monitoring agent — asking for a type the platform will not give it. SOCK_RAW is the usual candidate, and it also requires privilege, so the failure may present as -1 instead depending on which check runs first.
• A client library or driver built for a different socket set.
• A restricted environment where a socket type is filtered rather than absent. In a container that is more likely to appear as EPERM (-1) or ENOSYS (-38), so the errno tells you which layer refused.
• A sqlhosts protocol entry whose implementation needs a type the platform lacks — more usually reported as -43.

Where a -44 appears with no custom code anywhere in the path, treat the value with the suspicion -33 describes: nothing in a normal connection path can produce it, so it may be residue rather than evidence.

Common Causes

1. Custom code requesting an unusual socket type, most often SOCK_RAW.
2. A socket type filtered by a container or security policy rather than absent.
3. A client library built against a different platform's socket set.
4. A stale errno, where nothing in the failing path could have produced this value.

Diagnostic Checks

Confirm the symbol, since errno 44 on Linux is a STREAMS value and unrelated:

python3 -c 'import os; print(44, os.strerror(44)); print(94, os.strerror(94))'

Trace the call. The socket type is named directly in the traced line, and nothing else will identify it:

strace -f -e trace=socket -p <pid> 2>&1 | grep -iE 'ESOCKTNOSUPPORT|EPROTONOSUPPORT|EPERM'

socket(AF_INET, SOCK_RAW, IPPROTO_ICMP) = -1 EPERM (Operation not permitted)

Note that a raw socket is frequently refused on privilege before it is refused on type, so a trace may show -1 where the code expected this error.

Check whether the environment is restricted:

grep -i seccomp /proc/<pid>/status
capsh --print 2>/dev/null | grep -i net_raw
cat /proc/1/cgroup

CAP_NET_RAW absent explains a refused raw socket without any question of platform support.

Identify the code making the call:

onstat -g dll
ps -ef | grep -E 'oninit|onbar|agent' | grep -v grep

And the engine's record:

tail -300 "$INFORMIXDIR/tmp/online.log"

Solutions / Resolution

1. Trace the call and read the type. Everything else depends on knowing which type was requested, and the traced line gives it in full.
2. Establish whether it is unsupported or unprivileged. A raw socket refused for lack of CAP_NET_RAW is -1, not this, and the remedies have nothing in common.
3. Question why the code wants that type. A database-adjacent process needing a raw socket is unusual and worth understanding before it is granted the capability to use one.
4. Do not grant CAP_NET_RAW to clear an error. It is a broad privilege, and giving it to a process running alongside a database instance deserves a decision rather than a workaround.
5. If no custom code is in the path, treat the number as residue — see -33. Nothing in the engine's normal connection handling can produce this, so the value most likely came from somewhere else.
6. In a container, check the namespace's capabilities rather than the host's.

Platform Note

Platform	This condition	Errno 44 there means
Linux	errno 94	ECHRNG — STREAMS-era, unrelated
Solaris, AIX, HP-UX	confirm on the host	confirm on the host
BSD, Darwin	errno 44	this condition

Task	Linux	Solaris	AIX
Trace socket()	strace -e socket	truss -t so_socket	truss -t socket
Capabilities	capsh --print	privileges: ppriv -S <pid>	role-based, lsrole

Solaris expresses the equivalent of CAP_NET_RAW through privileges (net_rawaccess), inspected with ppriv. The concept transfers; the tooling does not.

Related Errors / Related Topics

• -43 — Protocol not supported. The neighbouring refusal, and the more likely of the two to arise from an Informix configuration. Note that on Linux errno 43 is EIDRM and means something considerably more serious.
• -46 and -47 — the family refusals, decided at the same moment.
• -45 — Operation not supported on socket, where the socket was created successfully and an operation on it was refused.

A -44 with no custom code in the path is more likely to be a misreported value than a socket problem. Trace first; if nothing requested an unusual socket type, the number is not the evidence it appears to be.