Hi, Rajini, Thanks for the reply. They all make sense.
5. Got it. Note that currently, only live brokers are registered in ZK. Another thing is that I am not sure that we want every broker to read all broker registrations directly from ZK. It's probably better to have the controller propagate this information. That will require changing the UpdateMetadataRequest protocol though. So, I am not sure if you want to do that in the same KIP. Jun On Fri, Dec 8, 2017 at 6:07 AM, Rajini Sivaram <rajinisiva...@gmail.com> wrote: > Hi Jun, > > Thank you for the review. > > 1. No, I am hoping to migrate partitions to new threads. We just need to > ensure they don't run concurrently. > > 2. AdminClient has a validateOnly option for AlterConfigs. Any exceptions > or return value of false from Reconfigurable#validate would fail the > AlterConfigsRequest. > > 3. Yes, we will support describe and alter of configs with listener prefix. > We will not allow alterConfigs() of security configs without the listener > prefix, since we need to prevent the whole cluster being made unusable. > > 4. Thank you, will make a note of that. > > 5. When we are upgrading (from 1.0 to 2.0 for example), my understanding is > that we set inter.broker.protocol.version=1.0, do a rolling upgrade of the > whole cluster and when all brokers are at 2.0, we do another rolling > upgrade with inter.broker.protocol.version=2.0. Jason's suggestion was to > avoid the second rolling upgrade by enabling dynamic update of > inter.broker.protocol.version. To set inter.broker.protocol.version=2.0 > dynamically, we need to verify not just that the current broker is on > version 2.0, but that all brokers int the cluster are on version 2.0 (I > thought that was the reason for the second rolling upgrade). The broker > version in ZK would enable that verification before performing the update. > > 6. The config source would be STATIC_BROKER_CONFIG/DYNAMIC_BROKER_CONFIG, > the config name would be listener.name.listenerA.configX. And synonyms > list > in describeConfigs() would list listener.name.listenerA.configX as well > as > configX. > > 7. I think `default` is an overused terminology already. When configs are > described, they return a flag indicating if the value is a default. And in > the broker, we have so many levels of configs already and we are adding so > many more, that it may be better to use a different term. It doesn't have > to be synonyms, but since we want to use the same term for topics and > brokers and we have listener configs which override non-prefixed security > configs, perhaps it is ok? > > Regards, > > Rajini > > > > On Wed, Dec 6, 2017 at 11:50 PM, Jun Rao <j...@confluent.io> wrote: > > > A couple more things. > > > > 6. For the SSL/SASL configurations with the listener prefix, do we need > > another level in config_source since it's neither topic nor broker? > > > > 7. For include_synonyms in DescribeConfigs, the name makes sense for the > > topic level configs. Not sure if it makes sense for other hierarchies. > > Perhaps sth more generic like default will be better? > > > > Thanks, > > > > Jun > > > > On Wed, Dec 6, 2017 at 3:41 PM, Jun Rao <j...@confluent.io> wrote: > > > > > Hi, Rajini, > > > > > > Thanks for the kip. Looks good overall. A few comments below. > > > > > > 1. "num.replica.fetchers: Affinity of partitions to threads will be > > > preserved for ordering." Does that mean the new fetcher threads won't > be > > > used until new partitions are added? This may be limiting. > > > > > > 2. I am wondering how the result from reporter.validate(Map<String, ?> > > > configs) will be used. If it returns false, do we return false to the > > admin > > > client for the validation call, which will seem a bit weird? > > > > > > 3. For the SSL and SASL configuration changes, do we support those with > > > the listener prefix (e.g., external-ssl-lisener.ssl. > keystore.location). > > > If so, do we plan to include them in the result of describeConfigs()? > > > > > > 4. "Updates to advertised.listeners will re-register the new listener > in > > > ZK". To support this, we will likely need additional logic in the > > > controller such that the controller can broadcast the metadata with the > > new > > > listeners to every broker. > > > > > > 5. Including broker version in broker registration in ZK. I am not sure > > > the usage of that. Each broker knows its version. So, is that for the > > > controller? > > > > > > Jun > > > > > > > > > > > > On Tue, Dec 5, 2017 at 11:05 AM, Colin McCabe <cmcc...@apache.org> > > wrote: > > > > > >> On Tue, Dec 5, 2017, at 06:01, Rajini Sivaram wrote: > > >> > Hi Colin, > > >> > > > >> > KAFKA-5722 already has an owner, so I didn't want to confuse the two > > >> > KIPs. They can be done independently of each other. The goal is to > > try > > >> and > > >> > validate every config to the minimum validation already in the > broker > > >> for > > >> > the static configs, but in some cases to a more restrictive level. > So > > a > > >> > typo like a file-not-found or class-not-found would definitely fail > > the > > >> > AlterConfigs request (validation is performed by AlterConfigs > > regardless > > >> > of validateOnly flag). I am working out the additional validation I > > can > > >> > perform as I implement updates for each config. For example, > > >> > inter-broker keystore update will not be allowed unless it can be > > >> > verified against the currently configured truststore. > > >> > > >> HI Rajini, > > >> > > >> I agree. It's probably better to avoid expanding the scope of > KIP-226. > > >> I hope we can get to KAFKA-5722 soon, though, since it will really > > >> improve the user experience for this feature. > > >> > > >> regards, > > >> Colin > > >> > > >> > > > >> > On Sat, Dec 2, 2017 at 10:15 PM, Colin McCabe <cmcc...@apache.org> > > >> wrote: > > >> > > > >> > > On Tue, Nov 28, 2017, at 14:48, Rajini Sivaram wrote: > > >> > > > Hi Colin, > > >> > > > > > >> > > > Thank you for reviewing the KIP. > > >> > > > > > >> > > > *kaka-configs.sh* will be converted to use *AdminClient* under > > >> > > > KAFKA-5722. > > >> > > > This is targeted for the next release (1.1.0). Under this KIP, > we > > >> will > > >> > > > implement *AdminClient#alterConfigs* for the dynamic configs > > listed > > >> in > > >> > > > the KIP. This will include validation of the configs and will > > return > > >> > > > appropriate errors if configs are invalid. Integration tests > will > > >> also be > > >> > > > added using AdmnClient. Only the actual conversion of > > ConfigCommand > > >> to > > >> > > > use AdminClient will be left to be done under KAFKA-5722. > > >> > > > > >> > > Hi Rajini, > > >> > > > > >> > > It seems like there is no KIP yet for KAFKA-5722. Does it make > > sense > > >> to > > >> > > describe the conversion of kafka-configs.sh to use AdminClient in > > >> > > KIP-226? Since the AlterConfigs RPCs already exist, it should be > > >> pretty > > >> > > straightforward. This would also let us add some information > about > > >> how > > >> > > errors will be handled, which is pretty important for users. For > > >> > > example, will kafka-configs.sh give an error if the user makes a > > typo > > >> > > when setting a configuration? > > >> > > > > >> > > > > > >> > > > Once KAFKA-5722 is implemented,* kafka-confgs.sh* can be used to > > >> obtain > > >> > > > the current configuration, which can be redirected to a text > file > > to > > >> > > create a > > >> > > > static *server.properties* file. This should help when > downgrading > > >> - but > > >> > > > it does require brokers to be running. We can also document how > to > > >> obtain > > >> > > > the properties using *zookeeper-shell.sh* while downgrading if > > >> brokers > > >> > > are > > >> > > > down. > > >> > > > > > >> > > > If we rename properties, we should add the new property to ZK > > based > > >> on > > >> > > > the value of the old property when the upgraded broker starts > up. > > >> But we > > >> > > > would probably leave the old property as is. The old property > will > > >> be > > >> > > returned > > >> > > > and used as a synonym only as long as the broker is on a version > > >> where it > > >> > > > is still valid. But it can remain in ZK and be updated if > > >> downgrading - > > >> > > > it will be up to the user to update the old property if > > downgrading > > >> or > > >> > > > delete it if not needed. Renaming properties is likely to be > > >> confusing > > >> > > in any > > >> > > > case even without dynamic configs, so hopefully it will be very > > >> rare. > > >> > > > > >> > > Sounds good. > > >> > > > > >> > > best, > > >> > > Colin > > >> > > > > >> > > > > > >> > > > > > >> > > > Rajini > > >> > > > > > >> > > > On Tue, Nov 28, 2017 at 7:47 PM, Colin McCabe < > cmcc...@apache.org > > > > > >> > > wrote: > > >> > > > > > >> > > > > Hi Rajini, > > >> > > > > > > >> > > > > This seems like a nice improvement! > > >> > > > > > > >> > > > > One thing that is a bit concerning is that, if > > >> bin/kafka-configs.sh is > > >> > > > > used, there is no way for the broker to give feedback or > error > > >> > > > > messages. The broker can't say "sorry, I can't reconfigure > that > > >> in > > >> > > that > > >> > > > > way." Or even "that configuration property is not > > reconfigurable > > >> in > > >> > > > > this version of the software." It seems like in the examples > > >> give, > > >> > > > > users will simply set a configuration using > > bin/kafka-configs.sh, > > >> but > > >> > > > > then they have to check the broker log files to see if it > could > > >> > > actually > > >> > > > > be applied. And even if it couldn't be applied, then it still > > >> lingers > > >> > > > > in ZooKeeper. > > >> > > > > > > >> > > > > This seems like it would lead to a lot of user confusion, > since > > >> they > > >> > > get > > >> > > > > no feedback when reconfiguring something. For example, there > > >> will be a > > >> > > > > lot of scenarios where someone finds a reconfiguration command > > on > > >> > > > > Google, runs it, but then it doesn't do anything because the > > >> software > > >> > > > > version is different. And there's no error message or > feedback > > >> about > > >> > > > > this. It just doesn't work. > > >> > > > > > > >> > > > > To prevent this, I think we should convert > bin/kafka-configs.sh > > >> to use > > >> > > > > AdminClient's AlterConfigsRequest. This allows us to detect > > >> scenarios > > >> > > > > where, because of a typo, different software version, or a > value > > >> of the > > >> > > > > wrong type (eg. string vs. int), the given configuration > cannot > > be > > >> > > > > applied. We really should convert kafka-configs.sh to use > > >> AdminClient > > >> > > > > anyway, for all the usual reasons-- people want to lock down > > >> ZooKeeper, > > >> > > > > ACLs should be enforced, internal representations should be > > >> hidden, we > > >> > > > > should support environments where ZK is not exposed, etc. etc. > > >> > > > > > > >> > > > > Another issue that I see here is, how does this interact with > > >> > > downgrade? > > >> > > > > Presumably, if the user downgrades to a version that doesn't > > >> support > > >> > > > > KIP-226, all the dynamic configurations stored in ZK revert to > > >> whatever > > >> > > > > value they have in the local config files. Do we need to > have a > > >> > > utility > > >> > > > > that can reify the actual applied configuration into a local > > text > > >> file, > > >> > > > > to make downgrades less painful? > > >> > > > > > > >> > > > > With regard to upgrades, what happens if we change the name > of a > > >> > > > > configuration key in the future? For example, if we decide to > > >> rename > > >> > > > > min.insync.replicas to min.in.sync.replicas, presumably we > will > > >> > > > > deprecate the old key name. And then perhaps it will be > removed > > >> in a > > >> > > > > future release, such as Apache Kafka 2.0. In this scenario, > > >> should the > > >> > > > > Kafka upgrade process change the name of the configuration key > > in > > >> ZK > > >> > > > > from min.insync.replicas to min.in.sync.replicas? Obviously > > this > > >> will > > >> > > > > make downgrades harder, if so. But if it doesn't, then > removing > > >> > > > > deprecated configuration key synonyms might become very > > difficult. > > >> > > > > > > >> > > > > best, > > >> > > > > Colin > > >> > > > > > > >> > > > > > > >> > > > > On Wed, Nov 22, 2017, at 12:52, Rajini Sivaram wrote: > > >> > > > > > Hi Tom, > > >> > > > > > > > >> > > > > > No, I am not proposing this as a way to configure > replication > > >> quotas. > > >> > > > > > When > > >> > > > > > you describe broker configs using AdminClient, you will see > > all > > >> the > > >> > > > > > configs > > >> > > > > > persisted in /configs/brokers/<brokerId> in ZooKeeper and > this > > >> > > includes > > >> > > > > > leader.replication.throttled.rate, follower.replication. > > >> > > throttled.rate > > >> > > > > > etc. But > > >> > > > > > the broker configs that can be altered using AdminClient as > a > > >> result > > >> > > of > > >> > > > > > this KIP are those explicitly stated in the KIP (does not > > >> include > > >> > > any of > > >> > > > > > the quota configs). > > >> > > > > > > > >> > > > > > Regards, > > >> > > > > > > > >> > > > > > Rajini > > >> > > > > > > > >> > > > > > On Wed, Nov 22, 2017 at 7:54 PM, Tom Bentley < > > >> t.j.bent...@gmail.com> > > >> > > > > > wrote: > > >> > > > > > > > >> > > > > > > Hi Rajini, > > >> > > > > > > > > >> > > > > > > Just to clarify, are you proposing this as a way to > > configure > > >> > > > > interbroker > > >> > > > > > > throttling/quotas? I don't think you are, just wanted to > > check > > >> > > (since > > >> > > > > > > KIP-179 proposes a different mechanism for setting them > > which > > >> > > supports > > >> > > > > > > their automatic removal). > > >> > > > > > > > > >> > > > > > > Cheers, > > >> > > > > > > > > >> > > > > > > Tom > > >> > > > > > > > > >> > > > > > > On 22 November 2017 at 18:28, Rajini Sivaram < > > >> > > rajinisiva...@gmail.com> > > >> > > > > > > wrote: > > >> > > > > > > > > >> > > > > > > > I have made an update to the KIP to optionally return > all > > >> the > > >> > > config > > >> > > > > > > > synonyms in *DescribeConfigsResponse*. The synonyms are > > >> returned > > >> > > in > > >> > > > > the > > >> > > > > > > > order of precedence. AlterConfigsResponse will not be > > >> modified > > >> > > by the > > >> > > > > > > KIP. > > >> > > > > > > > Since many configs already have various overrides (e.g. > > >> topic > > >> > > configs > > >> > > > > > > with > > >> > > > > > > > broker overrides, security properties with listener name > > >> > > overrides) > > >> > > > > and > > >> > > > > > > we > > >> > > > > > > > will be adding more levels with dynamic configs, it will > > be > > >> > > useful to > > >> > > > > > > > obtain the full list in order of precedence. > > >> > > > > > > > > > >> > > > > > > > On Tue, Nov 21, 2017 at 11:24 AM, Rajini Sivaram < > > >> > > > > > > rajinisiva...@gmail.com> > > >> > > > > > > > wrote: > > >> > > > > > > > > > >> > > > > > > > > Hi Ted, > > >> > > > > > > > > > > >> > > > > > > > > You can quote the config name, but it is not necessary > > for > > >> > > > > deleting a > > >> > > > > > > > > config since the name doesn't contain any special > > >> characters > > >> > > that > > >> > > > > > > > requires > > >> > > > > > > > > quoting. > > >> > > > > > > > > > > >> > > > > > > > > On Mon, Nov 20, 2017 at 9:20 PM, Ted Yu < > > >> yuzhih...@gmail.com> > > >> > > > > wrote: > > >> > > > > > > > > > > >> > > > > > > > >> Thanks for the quick response. > > >> > > > > > > > >> > > >> > > > > > > > >> It seems the config following --delete-config should > be > > >> > > quoted. > > >> > > > > > > > >> > > >> > > > > > > > >> Cheers > > >> > > > > > > > >> > > >> > > > > > > > >> On Mon, Nov 20, 2017 at 12:02 PM, Rajini Sivaram < > > >> > > > > > > > rajinisiva...@gmail.com > > >> > > > > > > > >> > > > >> > > > > > > > >> wrote: > > >> > > > > > > > >> > > >> > > > > > > > >> > Ted, > > >> > > > > > > > >> > > > >> > > > > > > > >> > Have added an example for --delete-config. > > >> > > > > > > > >> > > > >> > > > > > > > >> > On Mon, Nov 20, 2017 at 7:42 PM, Ted Yu < > > >> > > yuzhih...@gmail.com> > > >> > > > > > > wrote: > > >> > > > > > > > >> > > > >> > > > > > > > >> > > bq. There is a --delete-config option > > >> > > > > > > > >> > > > > >> > > > > > > > >> > > Consider adding a sample with the above option to > > >> the KIP. > > >> > > > > > > > >> > > > > >> > > > > > > > >> > > Thanks > > >> > > > > > > > >> > > > > >> > > > > > > > >> > > On Mon, Nov 20, 2017 at 11:36 AM, Rajini Sivaram > < > > >> > > > > > > > >> > rajinisiva...@gmail.com> > > >> > > > > > > > >> > > wrote: > > >> > > > > > > > >> > > > > >> > > > > > > > >> > > > Hi Ted, > > >> > > > > > > > >> > > > > > >> > > > > > > > >> > > > Thank you for reviewing the KIP. > > >> > > > > > > > >> > > > > > >> > > > > > > > >> > > > *Would decreasing network/IO threads be > supported > > >> ?* > > >> > > > > > > > >> > > > Yes, As described in the KIP, some connections > > >> will be > > >> > > > > closed if > > >> > > > > > > > >> > network > > >> > > > > > > > >> > > > thread count is reduced (and reconnections will > > be > > >> > > > > processed on > > >> > > > > > > > >> > remaining > > >> > > > > > > > >> > > > threads) > > >> > > > > > > > >> > > > > > >> > > > > > > > >> > > > *What if some keys in configs are not in the > Set > > >> > > returned > > >> > > > > > > > >> > > > by reconfigurableConfigs()? Would exception be > > >> thrown ?* > > >> > > > > > > > >> > > > No, *reconfigurableConfigs() *will be used to > > >> decide > > >> > > which > > >> > > > > > > classes > > >> > > > > > > > >> are > > >> > > > > > > > >> > > > notified when a configuration update is made*. > > >> > > > > > > > >> > **reconfigure(Map<String, > > >> > > > > > > > >> > > ?> > > >> > > > > > > > >> > > > configs)* will be invoked with all of the > > >> configured > > >> > > > > configs of > > >> > > > > > > > the > > >> > > > > > > > >> > > broker, > > >> > > > > > > > >> > > > similar to *configure(Map<String, ?> > configs). > > >> *For > > >> > > > > example, > > >> > > > > > > > when > > >> > > > > > > > >> > > > *SslChannelBuilder* is made reconfigurable, it > > >> could > > >> > > just > > >> > > > > > > create a > > >> > > > > > > > >> new > > >> > > > > > > > >> > > > SslFactory with the latest configs, using the > > same > > >> code > > >> > > as > > >> > > > > > > > >> > *configure()*. > > >> > > > > > > > >> > > > We avoid reconfiguring *SslChannelBuilder > > >> > > *unnecessarily*, > > >> > > > > *for > > >> > > > > > > > >> example > > >> > > > > > > > >> > > if > > >> > > > > > > > >> > > > a topic config has changed, since topic configs > > >> are not > > >> > > > > listed > > >> > > > > > > in > > >> > > > > > > > >> the > > >> > > > > > > > >> > > > *SslChannelBuilder#**reconfigurableConfigs().* > > >> > > > > > > > >> > > > > > >> > > > > > > > >> > > > *The sample commands for bin/kafka-configs > > include > > >> > > > > > > '--add-config'. > > >> > > > > > > > >> > Would > > >> > > > > > > > >> > > > there be '--remove-config' ?* > > >> > > > > > > > >> > > > bin/kafka-configs.sh is an existing tool whose > > >> > > parameters > > >> > > > > will > > >> > > > > > > not > > >> > > > > > > > >> be > > >> > > > > > > > >> > > > modified by this KIP. There is a > --delete-config > > >> option. > > >> > > > > > > > >> > > > > > >> > > > > > > > >> > > > *ssl.keystore.password appears a few lines > above. > > >> Would > > >> > > > > there be > > >> > > > > > > > any > > >> > > > > > > > >> > > > issue with mixture of connections (with old and > > new > > >> > > > > password) ?* > > >> > > > > > > > >> > > > No, passwords (and the actual keystore) are > only > > >> used > > >> > > during > > >> > > > > > > > >> > > > authentication. Any channel created using the > old > > >> > > SslFactory > > >> > > > > > > will > > >> > > > > > > > >> not > > >> > > > > > > > >> > be > > >> > > > > > > > >> > > > impacted. > > >> > > > > > > > >> > > > > > >> > > > > > > > >> > > > Regards, > > >> > > > > > > > >> > > > > > >> > > > > > > > >> > > > Rajini > > >> > > > > > > > >> > > > > > >> > > > > > > > >> > > > > > >> > > > > > > > >> > > > On Mon, Nov 20, 2017 at 4:39 PM, Ted Yu < > > >> > > > > yuzhih...@gmail.com> > > >> > > > > > > > >> wrote: > > >> > > > > > > > >> > > > > > >> > > > > > > > >> > > > > bq. (e.g. increase network/IO threads) > > >> > > > > > > > >> > > > > > > >> > > > > > > > >> > > > > Would decreasing network/IO threads be > > supported > > >> ? > > >> > > > > > > > >> > > > > > > >> > > > > > > > >> > > > > bq. void reconfigure(Map<String, ?> > > configs); > > >> > > > > > > > >> > > > > > > >> > > > > > > > >> > > > > What if some keys in configs are not in the > Set > > >> > > returned > > >> > > > > by > > >> > > > > > > > >> > > > > reconfigurableConfigs() > > >> > > > > > > > >> > > > > ? Would exception be thrown ? > > >> > > > > > > > >> > > > > If so, please specify which exception would > be > > >> thrown. > > >> > > > > > > > >> > > > > > > >> > > > > > > > >> > > > > The sample commands for bin/kafka-configs > > include > > >> > > > > > > > '--add-config'. > > >> > > > > > > > >> > > > > Would there be '--remove-config' ? > > >> > > > > > > > >> > > > > > > >> > > > > > > > >> > > > > bq. Existing connections will not be > affected, > > >> new > > >> > > > > connections > > >> > > > > > > > >> will > > >> > > > > > > > >> > use > > >> > > > > > > > >> > > > the > > >> > > > > > > > >> > > > > new keystore. > > >> > > > > > > > >> > > > > > > >> > > > > > > > >> > > > > ssl.keystore.password appears a few lines > > above. > > >> Would > > >> > > > > there > > >> > > > > > > be > > >> > > > > > > > >> any > > >> > > > > > > > >> > > issue > > >> > > > > > > > >> > > > > with mixture of connections (with old and new > > >> > > password) ? > > >> > > > > > > > >> > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > > > >> > > > > Cheers > > >> > > > > > > > >> > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > > > >> > > > > On Mon, Nov 20, 2017 at 5:57 AM, Rajini > > Sivaram < > > >> > > > > > > > >> > > rajinisiva...@gmail.com > > >> > > > > > > > >> > > > > > > >> > > > > > > > >> > > > > wrote: > > >> > > > > > > > >> > > > > > > >> > > > > > > > >> > > > > > Hi all, > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > I have submitted KIP-226 to enable dynamic > > >> > > > > reconfiguration > > >> > > > > > > of > > >> > > > > > > > >> > brokers > > >> > > > > > > > >> > > > > > without restart: > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > https://cwiki.apache.org/ > > >> > > confluence/display/KAFKA/KIP- > > >> > > > > > > > >> > > > > > 226+-+Dynamic+Broker+Configuration > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > The KIP proposes to extend the current > > dynamic > > >> > > > > replication > > >> > > > > > > > quota > > >> > > > > > > > >> > > > > > configuration for brokers to support > dynamic > > >> > > > > reconfiguration > > >> > > > > > > > of > > >> > > > > > > > >> a > > >> > > > > > > > >> > > > limited > > >> > > > > > > > >> > > > > > set of configuration options that are > > typically > > >> > > updated > > >> > > > > > > during > > >> > > > > > > > >> the > > >> > > > > > > > >> > > > > lifetime > > >> > > > > > > > >> > > > > > of a broker. > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > Feedback and suggestions are welcome. > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > Thank you... > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > Regards, > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > Rajini > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > > > >> > > > > > >> > > > > > > > >> > > > > >> > > > > > > > >> > > > >> > > > > > > > >> > > >> > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > >> > > > > >> > > > > > > > > >
