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SNOW-4058589: retry SSLError "Unexpected EOF" during TLS handshake - #3027
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A TLS handshake terminated by the peer surfaces in pyOpenSSL as
SSLError("bad handshake: SysCallError(-1, 'Unexpected EOF')"). The retry
gate only recognized "ECONNRESET" in repr(e), so this handshake failure
was classified non-retryable and raised OperationalError (errno 250003)
instead of being retried like ECONNRESET.
Widen the gate on both the sync (network.py) and async (aio/_network.py)
request paths to also retry when "Unexpected EOF" is present in repr(se).
Tests: add test_sslerror_with_unexpected_eof_retries and rename the
negative test to
test_sslerror_without_econnreset_or_unexpected_eof_does_not_retry,
on both sync and async paths. Add DESCRIPTION.md release note.
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September 4, 2026 08:49
| raw_ret.close() # ensure response is closed | ||
| except (aiohttp.ClientSSLError, aiohttp.ClientConnectorSSLError) as se: | ||
| if is_econnreset_exception(se): | ||
| if is_econnreset_exception(se) or "Unexpected EOF" in repr(se): |
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Let's make it into is_unexpected_eof_exception to keep it aligned
Address review feedback on PR #3027: replace the inline "Unexpected EOF" in repr() check with a named is_unexpected_eof_exception() predicate, mirroring is_econnreset_exception, in both the sync and async SSLError retry handlers. No behavior change. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
sfc-gh-turbaszek
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Sep 4, 2026
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Problem
SnowflakeRestful._request_execonly retries anSSLErrorwhen itsrepr()containsECONNRESET. A TLS handshake aborted by the peer surfaces (via pyOpenSSL) asSSLError("bad handshake: SysCallError(-1, 'Unexpected EOF')"), which does not match — so it is treated as non-retryable and raised asOperationalError(errno 250003).Impact
When the peer closes the connection mid-TLS-handshake — a transient, retryable condition — the request fails immediately instead of being retried, surfacing as a hard connection error. Affects both the sync and async request paths.
We got a customer complaint due to this.
Fix
Retry when
"Unexpected EOF"is present inrepr(se), alongside the existingECONNRESETcheck, innetwork.py(sync) andaio/_network.py(async).Tests
test_sslerror_with_unexpected_eof_retries(sync + async), assertingRetryRequest.test_sslerror_without_econnreset_or_unexpected_eof_does_not_retry.test_retry_networkunit tests pass (43, sync + async).