Hi team, we met an error snappy: corrupt input while

How to debug snappy: corrupt input? about snappy HOT 2 OPEN

golang commented on July 19, 2024

How to debug snappy: corrupt input?

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Comments (2)

xiaoxiaoHe-E commented on July 19, 2024

I think we figure out the reason now:

How to reproduce the issue:

tcpkill the according connection
use tc to make network packages corrupt

sudo tc qdisc add dev ens192 root netem corrupt 30%

So the snappy can always report the error snappy: corrupt input in our environment.

Misleading error message `corrupt input`

We get this error from here. But the real reason is that snappy read from a closed connection and get an empty data next time. So cannot decode incomplete data correctly. We think it's better to report an ununexpected EOF error here.

Here is the code we modified during testing:

diff --git a/decode.go b/decode.go
index 23c6e26..208f054 100644
--- a/decode.go
+++ b/decode.go
@@ -13,6 +13,7 @@ import (
 var (
        // ErrCorrupt reports that the input is invalid.
        ErrCorrupt = errors.New("snappy: corrupt input")
+       ErrEof = errors.New("snappy: unexpected EOF")
        // ErrTooLarge reports that the uncompressed length is too large.
        ErrTooLarge = errors.New("snappy: decoded block is too large")
        // ErrUnsupported reports that the input isn't supported.
@@ -111,7 +112,7 @@ func (r *Reader) Reset(reader io.Reader) {
 func (r *Reader) readFull(p []byte, allowEOF bool) (ok bool) {
        if _, r.err = io.ReadFull(r.r, p); r.err != nil {
                if r.err == io.ErrUnexpectedEOF || (r.err == io.EOF && !allowEOF) {
-                       r.err = ErrCorrupt
+                       r.err = ErrEof
                }
                return false
        }
(END)

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