Motivation:
If we don't need the scheduled future, then it will be one less complication when we change Netty Future to no longer extend JDK Future.
It would also result in fewer elements in our API.
Modification:
There was only one real use of ScheduledFuture in our code, in Cache.
This has been changed to wrap an ordinary future with a deadline for implementing the Delayed interface.
All other places were effectively overspecifying by relying on ScheduledFuture.
A few places were also specifying JDK Futures - these have been changed to specify Netty Futures.
Result:
Reduced dependency on the ScheduledFuture interfaces.
Motivation:
NullChecks resulting in a NullPointerException or IllegalArgumentException, numeric ranges (>0, >=0) checks, not empty strings/arrays checks must never be anonymous but with the parameter or variable name which is checked. They must be specific and should not be done with an "OR-Logic" (if a == null || b == null) throw new NullPointerEx.
Modifications:
* import static relevant checks
* Replace manual checks with ObjectUtil methods
Result:
All checks needed are done with ObjectUtil, some exception texts are improved.
Fixes#11170
Motivation:
HTTP is a plaintext protocol which means that someone may be able
to eavesdrop the data. To prevent this, HTTPS should be used whenever
possible. However, maintaining using https:// in all URLs may be
difficult. The nohttp tool can help here. The tool scans all the files
in a repository and reports where http:// is used.
Modifications:
- Added nohttp (via checkstyle) into the build process.
- Suppressed findings for the websites
that don't support HTTPS or that are not reachable
Result:
- Prevent using HTTP in the future.
- Encourage users to use HTTPS when they follow the links they found in
the code.
Motivation:
Traffic shaping needs more accurate execution than scheduled one. So the
use of FixedRate instead.
Moreover the current implementation tends to create as many threads as
channels use a ChannelTrafficShapingHandlern, which is unnecessary.
Modifications:
Change the executor.schedule to executor.scheduleAtFixedRate in the
start and remove the reschedule call from run monitor thread since it
will be restarted by the Fixed rate executor.
Also fix a minor bug where restart was only doing start() without stop()
before.
Result:
Threads are more stable in number of cached and precision of traffic
shaping is enhanced.
Motivation:
We can just use Objects.requireNonNull(...) as a replacement for ObjectUtil.checkNotNull(....)
Modifications:
- Use Objects.requireNonNull(...)
Result:
Less code to maintain.
In TrafficCounter, a recent change makes the contract of the API (the
constructor) wrong and lead to issue with GlobalChannelTrafficCounter
where executor must be null.
Motivation:
TrafficCounter executor argument in constructor might be null, as
explained in the API, for some particular cases where no executor are
needed (relevant tasks being taken by the caller as in
GlobalChannelTrafficCounter).
A null pointer exception is raised while it should not since it is
legal.
Modifications:
Remove the 2 null checking for this particular attribute.
Note that when null, the attribute is not reached nor used (a null
checking condition later on is applied).
Result:
No more null exception raized while it should not.
This shall be made also to 4.0, 4.1 (present) and master. 3.10 is not
concerned.
Related: #3476
Motivation:
Some users use TrafficCounter for other uses than we originally
intended, such as implementing their own traffic shaper. In such a
case, a user does not want to specify an AbstractTrafficShapingHandler.
Modifications:
- Add a new constructor that does not require an
AbstractTrafficShapingHandler, so that a user can use it without it.
- Simplify TrafficMonitoringTask
- Javadoc cleanup
Result:
We open the possibility of using TrafficCounter for other purposes than
just using it with AbstractTrafficShapingHandler. Eventually, we could
generalize it a little bit more, so that we can potentially use it for
other uses.
Motivation:
Several issues were shown by various ticket (#2900#2956).
Also use the improvement on writability user management from #3036.
And finally add a mixte handler, both for Global and Channels, with
the advantages of being uniquely created and using less memory and
less shaping.
Issue #2900
When a huge amount of data are written, the current behavior of the
TrafficShaping handler is to limit the delay to 15s, whatever the delay
the previous write has. This is wrong, and when a huge amount of writes
are done in a short time, the traffic is not correctly shapened.
Moreover, there is a high risk of OOM if one is not using in his/her own
handler for instance ChannelFuture.addListener() to handle the write
bufferisation in the TrafficShapingHandler.
This fix use the "user-defined writability flags" from #3036 to
allow the TrafficShapingHandlers to "user-defined" managed writability
directly, as for reading, thus using the default isWritable() and
channelWritabilityChanged().
This allows for instance HttpChunkedInput to be fully compatible.
The "bandwidth" compute on write is only on "acquired" write orders, not
on "real" write orders, which is wrong from statistic point of view.
Issue #2956
When using GlobalTrafficShaping, every write (and read) are
synchronized, thus leading to a drop of performance.
ChannelTrafficShaping is not touched by this issue since synchronized is
then correct (handler is per channel, so the synchronized).
Modifications:
The current write delay computation takes into account the previous
write delay and time to check is the 15s delay (maxTime) is really
exceeded or not (using last scheduled write time). The algorithm is
simplified and in the same time more accurate.
This proposal uses the #3036 improvement on user-defined writability
flags.
When the real write occurs, the statistics are update accordingly on a
new attribute (getRealWriteThroughput()).
To limit the synchronisations, all synchronized on
GlobalTrafficShapingHandler on submitWrite were removed. They are
replaced with a lock per channel (since synchronization is still needed
to prevent unordered write per channel), as in the sendAllValid method
for the very same reason.
Also all synchronized on TrafficCounter on read/writeTimeToWait() are
removed as they are unnecessary since already locked before by the
caller.
Still the creation and remove operations on lock per channel (PerChannel
object) are synchronized to prevent concurrency issue on this critical
part, but then limited.
Additionnal changes:
1) Use System.nanoTime() instead of System.currentTimeMillis() and
minimize calls
2) Remove / 10 ° 10 since no more sleep usage
3) Use nanoTime instead of currentTime such that time spend is computed,
not real time clock. Therefore the "now" relative time (nanoTime based)
is passed on all sub methods.
4) Take care of removal of the handler to force write all pending writes
and release read too
8) Review Javadoc to explicit:
- recommandations to take into account isWritable
- recommandations to provide reasonable message size according to
traffic shaping limit
- explicit "best effort" traffic shaping behavior when changing
configuration dynamically
Add a MixteGlobalChannelTrafficShapingHandler which allows to use only one
handler for mixing Global and Channel TSH. I enables to save more memory and
tries to optimize the traffic among various channels.
Result:
The traffic shaping is more stable, even with a huge number of writes in
short time by taking into consideration last scheduled write time.
The current implementation of TrafficShapingHandler using user-defined
writability flags and default isWritable() and
fireChannelWritabilityChanged works as expected.
The statistics are more valuable (asked write vs real write).
The Global TrafficShapingHandler should now have less "global"
synchronization, hoping to the minimum, but still per Channel as needed.
The GlobalChannel TrafficShapingHandler allows to have only one handler for all channels while still offering per channel in addition to global traffic shaping.
And finally maintain backward compatibility.
Motivation:
Currently the last read/write throughput is calculated by first division,this will be 0 if the last read/write bytes < interval,change the order will get the correct result
Modifications:
Change the operator order from first do division to multiplication
Result:
Get the correct result instead of 0 when bytes are smaller than interval
Motivation:
Currently Traffic Shaping is using 1 timer only and could lead to
"partial" wrong bandwidth computation when "short" time occurs between
adding used bytes and when the TrafficCounter updates itself and finally
when the traffic is computed.
Indeed, the TrafficCounter is updated every x delay and it is at the
same time saved into "lastXxxxBytes" and set to 0. Therefore, when one
request the counter, it first updates the TrafficCounter with the added
used bytes. If this value is set just before the TrafficCounter is
updated, then the bandwidth computation will use the TrafficCounter with
a "0" value (this value being reset once the delay occurs). Therefore,
the traffic shaping computation is wrong in rare cases.
Secondly the traffic shapping should avoid if possible the "Timeout"
effect by not stopping reading or writing more than a maxTime, this
maxTime being less than the TimeOut limit.
Thirdly the traffic shapping in read had an issue since the readOp
was not set but should, turning in no read blocking from socket
point of view.
Modifications:
The TrafficCounter has 2 new methods that compute the time to wait
according to read or write) using in priority the currentXxxxBytes (as
before), but could used (if current is at 0) the lastXxxxxBytes, and
therefore having more chance to take into account the real traffic.
Moreover the Handler could change the default "max time to wait", which
is by default set to half of "standard" Time Out (30s:2 = 15s).
Finally we add the setAutoRead(boolean) accordingly to the situation,
as proposed in #2696 (this pull request is in error for unknown reason).
Result:
The Traffic Shaping is better take into account (no 0 value when it
shouldn't) and it tries to not block traffic more than Time Out event.
Moreover the read is really stopped from socket point of view.
This version is similar to #2388 and #2450.
This version is for V4.1, and includes the #2696 pull request
to ease the merge process.
It is compatible with master too.
Including also #2748
The test minimizes time check by reducing to 66ms steps (55s).
Motivation:
Message from FindBugs:
This method performs synchronization an object that is an instance of a class from the java.util.concurrent package (or its subclasses). Instances of these classes have their own concurrency control mechanisms that are orthogonal to the synchronization provided by the Java keyword synchronized. For example, synchronizing on an AtomicBoolean will not prevent other threads from modifying the AtomicBoolean.
Such code may be correct, but should be carefully reviewed and documented, and may confuse people who have to maintain the code at a later date.
Modification:
Use synchronized(this)
Result:
Less confusing code
Split the project into the following modules:
* common
* buffer
* codec
* codec-http
* transport
* transport-*
* handler
* example
* testsuite (integration tests that involve 2+ modules)
* all (does nothing yet, but will make it generate netty.jar)
This commit also fixes the compilation errors with transport-sctp on
non-Linux systems. It will at least compile without complaints.