- Since the first flush failure, if the accumulated consecutive failure count exceeds the value defined in knobs, it will trigger the current worker process to report this issue via the 'GetServerDBInfo' interface of the cluster controler
- A successful flush will reset the accumulated counter.
Notice that the current solution does not take the time into consideration. The assumption is that flush failures tend to only happen in a clustered manner. The intermittent, but short, periods of flush failures are not considered as a problem since the memory pressure built by them should be negligible.
This option allows clients to select the clock source for trace events
similar to the `--traceclock` command line parameter for `fdbserver`.
Using the `realtime` clock sources makes loading event data into
OpenTracing systems like Jaeger more useful.
This is the first part of making `TraceEvent` cheaper. The main idea is
to defer calls to any code that formats string. These are the main
changes:
- TraceEvent::detail now takes a c-string instead of std::string for
literals. This prevents unnecessary allocations if the trace is not
going to be printed in the first place (for example for SevDebug).
Before that `detail` expected a `std::string` as key, which mean that
any string literal would be copied on each call.
- Templates Traceable and SpecialTraceMetricType. These templates can be
specialized for any type that needs to be printed. The actual
formatting will be deferred to after the `enabled` check. This
provides two benefits: (1) if a TraceEvent is disabled, we don't pay
for the formatting and (2) TraceEvent can trace types that it doesn't
know about.
- TraceEvent::enabled will be set in the constructor if the Severity is
passed. This will make sure that `TraceEvent::init` is not called.
- `TraceEvent::detail` will be inlined. So for disabled TraceEvent
calls, a call to detail will only introduce a if-branch which is much
cheaper than a function call.
':' is not acceptable on Windows. Reason to choose '_' instead of '.'
is to differentiate b/w IPv4 and IPv6 easily, and also '..1' in
filename looks weirder than '__1', which would happen with shortened
IPv6 addresses. And non-shortened IPv6 addreses are just lots of 0s.
- NetworkAddress now contains IPAddress object which can be either
IPv4 or IPv6 address. 128bits are used even for IPv4 addresses,
however only 32bits are used when using/serializing IPv4 address.
- ConnectPacket is updated to store IPv6 address. Backward compatible
with old format since the first 32bits of IP address field is used
for serialization of IPv4.
- Mainly updates rest of the code to use IPAddress structure instead
of plain uint32_t.
- IPv6 address/pair ports should be represented as `[ip]:port` as per
convention. This applies to both cluster files and command line
arguments.
Remove the use of relative paths. A header at foo/bar.h could be included by
files under foo/ with "bar.h", but would be included everywhere else as
"foo/bar.h". Adjust so that every include references such a header with the
latter form.
Signed-off-by: Robert Escriva <rescriva@dropbox.com>
* Detail names now all start with an uppercase character and contain no underscores. Ideally these should be head-first camel case, though that was harder to check.
* Type names have the same rules, except they allow one underscore (to support a usage pattern Context_Type). The first character after the underscore is also uppercase.
* Use seconds instead of milliseconds in details.
Added a check when events are logged in simulation that logs a message to stderr if the first two rules above aren't followed.
This probably doesn't address every instance of the above problems, but all of the events I was able to hit in simulation pass the check.
This means that loops like `seed=1; while ./fdbserver -r simulation -s $seed;
do seed=$(($seed+1)); done` to find an example of an often failing test. This
also means joshua will report ExitCode errors on anything that has a SevError
in the log.
As a part of this, we also implicitly downgrade any injected errors to SevWarnAlways.
Added an optimization to use a separate set for throttled events. Since this set is expected to be small, comparison of every event against this set is going to be cheaper.
Trace Events are sampled and cached with an expiration set. Every TraceEvent above SevDebug is checked against this cache to see if it exceeded a set threshold. If yes, then throttle the TraceEvent.
If a TraceEvent is throttled, a warning msg is logged.
Xin Dong