the RRL test included a test case that tried to start named with
a broken configuration. the same error could be found with
named-checkconf, so it should have been tested in the checkconf
system test.
It was discovered that the TTL-based cleaning could build up
a significant backlog of the rdataset headers during the periods where
the top of the TTL heap isn't expired yet. Make the TTL-based cleaning
more aggressive by cleaning more headers from the heap when we are
adding new header into the RBTDB.
It was discovered that an expired header could sit on top of the heap
a little longer than desireable. Remove expired headers (headers with
rdh_ttl set to 0) from the heap completely, so they don't block the next
TTL-based cleaning.
Instead of juggling with node locks in a cycle, cleanup the node we are
just pruning and send any the parent that's also subject to the pruning
to the prune tree via normal way (e.g. enqueue pruning on the parent).
This simplifies the code and also spreads the pruning load across more
event loop ticks which is better for lock contention as less things run
in a tight loop.
The log message for commit 24381cc36d8528f5a4046fb2614451aeac4cdfc1
explained:
In some older BIND 9 branches, the extra queuing overhead eliminated by
this change could be remotely exploited to cause excessive memory use.
Due to architectural shift, this branch is not vulnerable to that issue,
but applying the fix to the latter is nevertheless deemed prudent for
consistency and to make the code future-proof.
However, it turned out that having a single queue for the nodes to be
pruned increased lock contention to a level where cleaning up nodes from
the RBTDB took too long, causing the amount of memory used by the cache
to grow indefinitely over time.
This commit reverts the change to the pruning mechanism introduced by
commit 24381cc36d8528f5a4046fb2614451aeac4cdfc1 as BIND branches newer
than 9.16 were not affected by the excessive event queueing overhead
issue mentioned in the log message for the above commit.
This commit improves the documentation on the ephemeral TLS
configuration and describes in more detail what is happening with TLS
configurations on reconfiguration in general.
When the first parametrized test takes a bit longer than usual, the zone
transfer in ns3 may succeed before the second parametrized test is even
started, and then watch_log_from_here() won't find the "Transfer status:
success" message in the named log. Using watch_log_from_start() instead
makes sure the test is more stable.
dns__cacherbt_expireheader can unlink / free header_prev underneath
it. Use ISC_LIST_TAIL after calling dns__cacherbt_expireheader
instead to get the next pointer to be processed.
This commit ensures that worker threads are not sleeping (by using
select()) when '-T transferslowly/transferstuck' test options are
used. This commit converts synchronous implementation of the code into
an asynchronous one based on timers.
The resolver's code was not ready to failures when trying to establish
a connection via TCP-based transports (e.g. when creating TLS contexts
before establishing a TLS connection).
This commit fixes that.
