Both Dell routes held a pooled connection open for the duration of the
vendor HTTP call. sync_dell was the severe case: bulk_lookup asks Dell
about 100 service tags per request and calls them sequentially, so a
fleet-sized sync pinned one connection for minutes. On gevent workers
that exhausts the pool and fails every request in the application, not
just warranty.
Copy the values the lookup needs into locals, commit to return the
connection, then reacquire for the writes. The locals are load-bearing:
a commit expires loaded attributes, so reading them afterwards would
quietly check a connection back out and restore the defect.
Preload the existing warranty links in one query. The write loop ran a
query per asset plus one per link, which would have traded the long
network hold for a long write transaction.
Transaction boundaries do not show up in behavioural tests, so the new
tests assert session state at the moment the provider is called. Both
were confirmed to fail against the unfixed code, including the
post-commit attribute-access variant that leaves all other tests green.
Single commit and the existing error handling are unchanged, so the
sync stays all-or-nothing.
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