Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
Yes I should, should't I ? :-) -- Edoardo Comar IBM Message Hub IBM UK Ltd, Hursley Park, SO21 2JN From: Rajini Sivaram To: dev Date: 18/09/2018 15:33 Subject:Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses Hi Edo, The KIP looks good, perhaps you can start vote on this to get it in time for 2.1.0? Regards, Rajini On Tue, Sep 18, 2018 at 1:58 PM, Eno Thereska wrote: > Got it, thanks! > > Eno > > On Tue, Sep 18, 2018 at 1:41 PM, Edoardo Comar wrote: > > > Hi Eno, > > > > we implement network separation and the machines fronting the brokers > > (call them LBs for simplicity) will route the connection to the correct > > broker based on the TLS SNI. We register in the DNS multiple A records > > (the IPs of all LBs) for each the brokers' hostnames. > > As long as all the brokers are up, the cluster is fully functioning even > > if just one of the LBs is up. > > > > HTH, > > Edo > > -- > > > > Edoardo Comar > > > > IBM Message Hub > > > > IBM UK Ltd, Hursley Park, SO21 2JN > > > > > > > > From: Eno Thereska > > To: dev@kafka.apache.org > > Date: 18/09/2018 10:24 > > Subject:Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all > > DNS resolved IP addresses > > > > > > > > Hi folks, > > > > Could you expand the motivation a bit? When would it make sense to use an > > LB in front of Kafka brokers? A client needs to access each broker > > directly > > to consume the data in that broker and cannot be redirected to another > > broker. What exact scenario are you seeing that needs this KIP? > > > > Thanks > > Eno > > > > On Tue, Sep 18, 2018 at 9:52 AM, Mickael Maison < > mickael.mai...@gmail.com> > > wrote: > > > > > Bumping this thread > > > > > > It's a relatively small change that would help cloud environments with > > > load balancers fronting brokers > > > On Tue, Sep 11, 2018 at 3:01 PM Edoardo Comar > > wrote: > > > > > > > > Hi all, > > > > after some time we updated KIP-302 to reuse the config key introduced > > by > > > > KIP-235, with a different value to avoid conflicts between the two. > > > > Also clarified the use of multiple IPs only of the same type > > (IPv4/IPv6). > > > > > > > > We'd appreciate a further review and discussion. > > > > Thanks! > > > > Edo > > > > > > > > > > > > On Fri, 25 May 2018 at 12:36, Edoardo Comar > > wrote: > > > > > > > > > Hi Jonathan, > > > > > I'm ok with an expandable enum for the config that could be > extended > > > > > in the future. > > > > > It is marginally better than multiple potentially conflicting > config > > > > > entries. > > > > > > > > > > Though as I think the change for KIP-302 is independent from > KIP-235 > > > > > and they do not conflict, > > > > > when we'll look back at it post 2.0 we may see if it is more > > valuable > > > > > to shoehorn its config in an expanded enum or not > > > > > > > > > > thanks, > > > > > Edo > > > > > > > > > > On 24 May 2018 at 16:50, Skrzypek, Jonathan > > > > > > > wrote: > > > > > > Hi, > > > > > > > > > > > > As Rajini suggested in the thread for KIP 235 (attached), we > could > > > try > > > > > to have an enum that would drive what does the client > > expands/resolves. > > > > > > > > > > > > I suggest a client config called client.dns.lookup with different > > > values > > > > > possible : > > > > > > > > > > > > - no : no dns lookup > > > > > > - hostnames.only : perform dns lookup on both bootstrap.servers > > and > > > > > advertised listeners > > > > > > - canonical.hostnames.only : perform dns lookup on both > > > > > bootstrap.servers and advertised listeners > > > > > > - bootstrap.hostnames.only : perform dns lookup on > > bootstrap.servers > > > > > list and expand it > > > > > > - bootstrap.canonical.hostnames.only : perform dns lookup on >
Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
Hi Edo, The KIP looks good, perhaps you can start vote on this to get it in time for 2.1.0? Regards, Rajini On Tue, Sep 18, 2018 at 1:58 PM, Eno Thereska wrote: > Got it, thanks! > > Eno > > On Tue, Sep 18, 2018 at 1:41 PM, Edoardo Comar wrote: > > > Hi Eno, > > > > we implement network separation and the machines fronting the brokers > > (call them LBs for simplicity) will route the connection to the correct > > broker based on the TLS SNI. We register in the DNS multiple A records > > (the IPs of all LBs) for each the brokers' hostnames. > > As long as all the brokers are up, the cluster is fully functioning even > > if just one of the LBs is up. > > > > HTH, > > Edo > > -- > > > > Edoardo Comar > > > > IBM Message Hub > > > > IBM UK Ltd, Hursley Park, SO21 2JN > > > > > > > > From: Eno Thereska > > To: dev@kafka.apache.org > > Date: 18/09/2018 10:24 > > Subject:Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all > > DNS resolved IP addresses > > > > > > > > Hi folks, > > > > Could you expand the motivation a bit? When would it make sense to use an > > LB in front of Kafka brokers? A client needs to access each broker > > directly > > to consume the data in that broker and cannot be redirected to another > > broker. What exact scenario are you seeing that needs this KIP? > > > > Thanks > > Eno > > > > On Tue, Sep 18, 2018 at 9:52 AM, Mickael Maison < > mickael.mai...@gmail.com> > > wrote: > > > > > Bumping this thread > > > > > > It's a relatively small change that would help cloud environments with > > > load balancers fronting brokers > > > On Tue, Sep 11, 2018 at 3:01 PM Edoardo Comar > > wrote: > > > > > > > > Hi all, > > > > after some time we updated KIP-302 to reuse the config key introduced > > by > > > > KIP-235, with a different value to avoid conflicts between the two. > > > > Also clarified the use of multiple IPs only of the same type > > (IPv4/IPv6). > > > > > > > > We'd appreciate a further review and discussion. > > > > Thanks! > > > > Edo > > > > > > > > > > > > On Fri, 25 May 2018 at 12:36, Edoardo Comar > > wrote: > > > > > > > > > Hi Jonathan, > > > > > I'm ok with an expandable enum for the config that could be > extended > > > > > in the future. > > > > > It is marginally better than multiple potentially conflicting > config > > > > > entries. > > > > > > > > > > Though as I think the change for KIP-302 is independent from > KIP-235 > > > > > and they do not conflict, > > > > > when we'll look back at it post 2.0 we may see if it is more > > valuable > > > > > to shoehorn its config in an expanded enum or not > > > > > > > > > > thanks, > > > > > Edo > > > > > > > > > > On 24 May 2018 at 16:50, Skrzypek, Jonathan > > > > > > > wrote: > > > > > > Hi, > > > > > > > > > > > > As Rajini suggested in the thread for KIP 235 (attached), we > could > > > try > > > > > to have an enum that would drive what does the client > > expands/resolves. > > > > > > > > > > > > I suggest a client config called client.dns.lookup with different > > > values > > > > > possible : > > > > > > > > > > > > - no : no dns lookup > > > > > > - hostnames.only : perform dns lookup on both bootstrap.servers > > and > > > > > advertised listeners > > > > > > - canonical.hostnames.only : perform dns lookup on both > > > > > bootstrap.servers and advertised listeners > > > > > > - bootstrap.hostnames.only : perform dns lookup on > > bootstrap.servers > > > > > list and expand it > > > > > > - bootstrap.canonical.hostnames.only : perform dns lookup on > > > > > bootstrap.servers list and expand it > > > > > > - advertised.listeners.hostnames.only : perform dns lookup on > > > advertised > > > > > listeners > > > > > > - advertised.listeners.canonical.hostnames.only : perform dns > > > lo
Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
Got it, thanks! Eno On Tue, Sep 18, 2018 at 1:41 PM, Edoardo Comar wrote: > Hi Eno, > > we implement network separation and the machines fronting the brokers > (call them LBs for simplicity) will route the connection to the correct > broker based on the TLS SNI. We register in the DNS multiple A records > (the IPs of all LBs) for each the brokers' hostnames. > As long as all the brokers are up, the cluster is fully functioning even > if just one of the LBs is up. > > HTH, > Edo > -- > > Edoardo Comar > > IBM Message Hub > > IBM UK Ltd, Hursley Park, SO21 2JN > > > > From: Eno Thereska > To: dev@kafka.apache.org > Date: 18/09/2018 10:24 > Subject: Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all > DNS resolved IP addresses > > > > Hi folks, > > Could you expand the motivation a bit? When would it make sense to use an > LB in front of Kafka brokers? A client needs to access each broker > directly > to consume the data in that broker and cannot be redirected to another > broker. What exact scenario are you seeing that needs this KIP? > > Thanks > Eno > > On Tue, Sep 18, 2018 at 9:52 AM, Mickael Maison > wrote: > > > Bumping this thread > > > > It's a relatively small change that would help cloud environments with > > load balancers fronting brokers > > On Tue, Sep 11, 2018 at 3:01 PM Edoardo Comar > wrote: > > > > > > Hi all, > > > after some time we updated KIP-302 to reuse the config key introduced > by > > > KIP-235, with a different value to avoid conflicts between the two. > > > Also clarified the use of multiple IPs only of the same type > (IPv4/IPv6). > > > > > > We'd appreciate a further review and discussion. > > > Thanks! > > > Edo > > > > > > > > > On Fri, 25 May 2018 at 12:36, Edoardo Comar > wrote: > > > > > > > Hi Jonathan, > > > > I'm ok with an expandable enum for the config that could be extended > > > > in the future. > > > > It is marginally better than multiple potentially conflicting config > > > > entries. > > > > > > > > Though as I think the change for KIP-302 is independent from KIP-235 > > > > and they do not conflict, > > > > when we'll look back at it post 2.0 we may see if it is more > valuable > > > > to shoehorn its config in an expanded enum or not > > > > > > > > thanks, > > > > Edo > > > > > > > > On 24 May 2018 at 16:50, Skrzypek, Jonathan > > > > > wrote: > > > > > Hi, > > > > > > > > > > As Rajini suggested in the thread for KIP 235 (attached), we could > > try > > > > to have an enum that would drive what does the client > expands/resolves. > > > > > > > > > > I suggest a client config called client.dns.lookup with different > > values > > > > possible : > > > > > > > > > > - no : no dns lookup > > > > > - hostnames.only : perform dns lookup on both bootstrap.servers > and > > > > advertised listeners > > > > > - canonical.hostnames.only : perform dns lookup on both > > > > bootstrap.servers and advertised listeners > > > > > - bootstrap.hostnames.only : perform dns lookup on > bootstrap.servers > > > > list and expand it > > > > > - bootstrap.canonical.hostnames.only : perform dns lookup on > > > > bootstrap.servers list and expand it > > > > > - advertised.listeners.hostnames.only : perform dns lookup on > > advertised > > > > listeners > > > > > - advertised.listeners.canonical.hostnames.only : perform dns > > lookup on > > > > advertised listeners > > > > > > > > > > I realize this is a bit heavy but this gives users the ability to > > pick > > > > and choose. > > > > > I didn't include a setting to mix hostnames and canonical > hostnames > > as > > > > I'm not sure there would be a valid use case. > > > > > > > > > > Alternatively, to have less possible values, we could have 2 > > parameters : > > > > > > > > > > - dns.lookup.type with values : hostname / canonical.host.name > > > > > - dns.lookup.behaviour : bootstrap.servers, advertised.listeners, > > both > > > > > > > > > > Thoughts ? >
Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
Hi Eno, we implement network separation and the machines fronting the brokers (call them LBs for simplicity) will route the connection to the correct broker based on the TLS SNI. We register in the DNS multiple A records (the IPs of all LBs) for each the brokers' hostnames. As long as all the brokers are up, the cluster is fully functioning even if just one of the LBs is up. HTH, Edo -- Edoardo Comar IBM Message Hub IBM UK Ltd, Hursley Park, SO21 2JN From: Eno Thereska To: dev@kafka.apache.org Date: 18/09/2018 10:24 Subject:Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses Hi folks, Could you expand the motivation a bit? When would it make sense to use an LB in front of Kafka brokers? A client needs to access each broker directly to consume the data in that broker and cannot be redirected to another broker. What exact scenario are you seeing that needs this KIP? Thanks Eno On Tue, Sep 18, 2018 at 9:52 AM, Mickael Maison wrote: > Bumping this thread > > It's a relatively small change that would help cloud environments with > load balancers fronting brokers > On Tue, Sep 11, 2018 at 3:01 PM Edoardo Comar wrote: > > > > Hi all, > > after some time we updated KIP-302 to reuse the config key introduced by > > KIP-235, with a different value to avoid conflicts between the two. > > Also clarified the use of multiple IPs only of the same type (IPv4/IPv6). > > > > We'd appreciate a further review and discussion. > > Thanks! > > Edo > > > > > > On Fri, 25 May 2018 at 12:36, Edoardo Comar wrote: > > > > > Hi Jonathan, > > > I'm ok with an expandable enum for the config that could be extended > > > in the future. > > > It is marginally better than multiple potentially conflicting config > > > entries. > > > > > > Though as I think the change for KIP-302 is independent from KIP-235 > > > and they do not conflict, > > > when we'll look back at it post 2.0 we may see if it is more valuable > > > to shoehorn its config in an expanded enum or not > > > > > > thanks, > > > Edo > > > > > > On 24 May 2018 at 16:50, Skrzypek, Jonathan > > > wrote: > > > > Hi, > > > > > > > > As Rajini suggested in the thread for KIP 235 (attached), we could > try > > > to have an enum that would drive what does the client expands/resolves. > > > > > > > > I suggest a client config called client.dns.lookup with different > values > > > possible : > > > > > > > > - no : no dns lookup > > > > - hostnames.only : perform dns lookup on both bootstrap.servers and > > > advertised listeners > > > > - canonical.hostnames.only : perform dns lookup on both > > > bootstrap.servers and advertised listeners > > > > - bootstrap.hostnames.only : perform dns lookup on bootstrap.servers > > > list and expand it > > > > - bootstrap.canonical.hostnames.only : perform dns lookup on > > > bootstrap.servers list and expand it > > > > - advertised.listeners.hostnames.only : perform dns lookup on > advertised > > > listeners > > > > - advertised.listeners.canonical.hostnames.only : perform dns > lookup on > > > advertised listeners > > > > > > > > I realize this is a bit heavy but this gives users the ability to > pick > > > and choose. > > > > I didn't include a setting to mix hostnames and canonical hostnames > as > > > I'm not sure there would be a valid use case. > > > > > > > > Alternatively, to have less possible values, we could have 2 > parameters : > > > > > > > > - dns.lookup.type with values : hostname / canonical.host.name > > > > - dns.lookup.behaviour : bootstrap.servers, advertised.listeners, > both > > > > > > > > Thoughts ? > > > > > > > > Jonathan Skrzypek > > > > > > > > > > > > -Original Message- > > > > From: Edoardo Comar [mailto:edoco...@gmail.com] > > > > Sent: 17 May 2018 23:50 > > > > To: dev@kafka.apache.org > > > > Subject: Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS > > > resolved IP addresses > > > > > > > > Hi Jonathan, > > > > > > > >> A solution might be to expose to users the choice of using hostname > or > > > canonical host name on both sides. > > > >> Say having one s
Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
Hi folks, Could you expand the motivation a bit? When would it make sense to use an LB in front of Kafka brokers? A client needs to access each broker directly to consume the data in that broker and cannot be redirected to another broker. What exact scenario are you seeing that needs this KIP? Thanks Eno On Tue, Sep 18, 2018 at 9:52 AM, Mickael Maison wrote: > Bumping this thread > > It's a relatively small change that would help cloud environments with > load balancers fronting brokers > On Tue, Sep 11, 2018 at 3:01 PM Edoardo Comar wrote: > > > > Hi all, > > after some time we updated KIP-302 to reuse the config key introduced by > > KIP-235, with a different value to avoid conflicts between the two. > > Also clarified the use of multiple IPs only of the same type (IPv4/IPv6). > > > > We'd appreciate a further review and discussion. > > Thanks! > > Edo > > > > > > On Fri, 25 May 2018 at 12:36, Edoardo Comar wrote: > > > > > Hi Jonathan, > > > I'm ok with an expandable enum for the config that could be extended > > > in the future. > > > It is marginally better than multiple potentially conflicting config > > > entries. > > > > > > Though as I think the change for KIP-302 is independent from KIP-235 > > > and they do not conflict, > > > when we'll look back at it post 2.0 we may see if it is more valuable > > > to shoehorn its config in an expanded enum or not > > > > > > thanks, > > > Edo > > > > > > On 24 May 2018 at 16:50, Skrzypek, Jonathan > > > wrote: > > > > Hi, > > > > > > > > As Rajini suggested in the thread for KIP 235 (attached), we could > try > > > to have an enum that would drive what does the client expands/resolves. > > > > > > > > I suggest a client config called client.dns.lookup with different > values > > > possible : > > > > > > > > - no : no dns lookup > > > > - hostnames.only : perform dns lookup on both bootstrap.servers and > > > advertised listeners > > > > - canonical.hostnames.only : perform dns lookup on both > > > bootstrap.servers and advertised listeners > > > > - bootstrap.hostnames.only : perform dns lookup on bootstrap.servers > > > list and expand it > > > > - bootstrap.canonical.hostnames.only : perform dns lookup on > > > bootstrap.servers list and expand it > > > > - advertised.listeners.hostnames.only : perform dns lookup on > advertised > > > listeners > > > > - advertised.listeners.canonical.hostnames.only : perform dns > lookup on > > > advertised listeners > > > > > > > > I realize this is a bit heavy but this gives users the ability to > pick > > > and choose. > > > > I didn't include a setting to mix hostnames and canonical hostnames > as > > > I'm not sure there would be a valid use case. > > > > > > > > Alternatively, to have less possible values, we could have 2 > parameters : > > > > > > > > - dns.lookup.type with values : hostname / canonical.host.name > > > > - dns.lookup.behaviour : bootstrap.servers, advertised.listeners, > both > > > > > > > > Thoughts ? > > > > > > > > Jonathan Skrzypek > > > > > > > > > > > > -Original Message- > > > > From: Edoardo Comar [mailto:edoco...@gmail.com] > > > > Sent: 17 May 2018 23:50 > > > > To: dev@kafka.apache.org > > > > Subject: Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS > > > resolved IP addresses > > > > > > > > Hi Jonathan, > > > > > > > >> A solution might be to expose to users the choice of using hostname > or > > > canonical host name on both sides. > > > >> Say having one setting that collapses functionalities from both KIPs > > > (bootstrap expansion + advertised lookup) > > > >> and an additional parameter that defines how the resolution is > > > performed, using getCanonicalHostName() or not. > > > > > > > > thanks sounds to me *less* simple than independent config options, > sorry. > > > > > > > > I would like to say once again that by itself KIP-302 only speeds up > > > > the client behavior that can happen anyway when the client restarts > > > > multiple times, > > > > as every time there is no guarantee that - in presence of multiple A &
Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
Bumping this thread It's a relatively small change that would help cloud environments with load balancers fronting brokers On Tue, Sep 11, 2018 at 3:01 PM Edoardo Comar wrote: > > Hi all, > after some time we updated KIP-302 to reuse the config key introduced by > KIP-235, with a different value to avoid conflicts between the two. > Also clarified the use of multiple IPs only of the same type (IPv4/IPv6). > > We'd appreciate a further review and discussion. > Thanks! > Edo > > > On Fri, 25 May 2018 at 12:36, Edoardo Comar wrote: > > > Hi Jonathan, > > I'm ok with an expandable enum for the config that could be extended > > in the future. > > It is marginally better than multiple potentially conflicting config > > entries. > > > > Though as I think the change for KIP-302 is independent from KIP-235 > > and they do not conflict, > > when we'll look back at it post 2.0 we may see if it is more valuable > > to shoehorn its config in an expanded enum or not > > > > thanks, > > Edo > > > > On 24 May 2018 at 16:50, Skrzypek, Jonathan > > wrote: > > > Hi, > > > > > > As Rajini suggested in the thread for KIP 235 (attached), we could try > > to have an enum that would drive what does the client expands/resolves. > > > > > > I suggest a client config called client.dns.lookup with different values > > possible : > > > > > > - no : no dns lookup > > > - hostnames.only : perform dns lookup on both bootstrap.servers and > > advertised listeners > > > - canonical.hostnames.only : perform dns lookup on both > > bootstrap.servers and advertised listeners > > > - bootstrap.hostnames.only : perform dns lookup on bootstrap.servers > > list and expand it > > > - bootstrap.canonical.hostnames.only : perform dns lookup on > > bootstrap.servers list and expand it > > > - advertised.listeners.hostnames.only : perform dns lookup on advertised > > listeners > > > - advertised.listeners.canonical.hostnames.only : perform dns lookup on > > advertised listeners > > > > > > I realize this is a bit heavy but this gives users the ability to pick > > and choose. > > > I didn't include a setting to mix hostnames and canonical hostnames as > > I'm not sure there would be a valid use case. > > > > > > Alternatively, to have less possible values, we could have 2 parameters : > > > > > > - dns.lookup.type with values : hostname / canonical.host.name > > > - dns.lookup.behaviour : bootstrap.servers, advertised.listeners, both > > > > > > Thoughts ? > > > > > > Jonathan Skrzypek > > > > > > > > > -Original Message- > > > From: Edoardo Comar [mailto:edoco...@gmail.com] > > > Sent: 17 May 2018 23:50 > > > To: dev@kafka.apache.org > > > Subject: Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS > > resolved IP addresses > > > > > > Hi Jonathan, > > > > > >> A solution might be to expose to users the choice of using hostname or > > canonical host name on both sides. > > >> Say having one setting that collapses functionalities from both KIPs > > (bootstrap expansion + advertised lookup) > > >> and an additional parameter that defines how the resolution is > > performed, using getCanonicalHostName() or not. > > > > > > thanks sounds to me *less* simple than independent config options, sorry. > > > > > > I would like to say once again that by itself KIP-302 only speeds up > > > the client behavior that can happen anyway when the client restarts > > > multiple times, > > > as every time there is no guarantee that - in presence of multiple A > > > DNS records - the same IP is returned. Attempting to use additiona IPs > > > if the first fail just makes client recovery faster. > > > > > > cheers > > > Edo > > > > > > On 17 May 2018 at 12:12, Skrzypek, Jonathan > > wrote: > > >> Yes, makes sense. > > >> You mentioned multiple times you see no overlap and no issue with your > > KIP, and that they solve different use cases. > > >> > > >> Appreciate you have an existing use case that would work, but we need > > to make sure this isn't confusing to users and that any combination will > > always work, across security protocols. > > >> > > >> A solution might be to expose to users the choice of using hostname or > > canonical host name on both sides. > &
Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
Hi all, after some time we updated KIP-302 to reuse the config key introduced by KIP-235, with a different value to avoid conflicts between the two. Also clarified the use of multiple IPs only of the same type (IPv4/IPv6). We'd appreciate a further review and discussion. Thanks! Edo On Fri, 25 May 2018 at 12:36, Edoardo Comar wrote: > Hi Jonathan, > I'm ok with an expandable enum for the config that could be extended > in the future. > It is marginally better than multiple potentially conflicting config > entries. > > Though as I think the change for KIP-302 is independent from KIP-235 > and they do not conflict, > when we'll look back at it post 2.0 we may see if it is more valuable > to shoehorn its config in an expanded enum or not > > thanks, > Edo > > On 24 May 2018 at 16:50, Skrzypek, Jonathan > wrote: > > Hi, > > > > As Rajini suggested in the thread for KIP 235 (attached), we could try > to have an enum that would drive what does the client expands/resolves. > > > > I suggest a client config called client.dns.lookup with different values > possible : > > > > - no : no dns lookup > > - hostnames.only : perform dns lookup on both bootstrap.servers and > advertised listeners > > - canonical.hostnames.only : perform dns lookup on both > bootstrap.servers and advertised listeners > > - bootstrap.hostnames.only : perform dns lookup on bootstrap.servers > list and expand it > > - bootstrap.canonical.hostnames.only : perform dns lookup on > bootstrap.servers list and expand it > > - advertised.listeners.hostnames.only : perform dns lookup on advertised > listeners > > - advertised.listeners.canonical.hostnames.only : perform dns lookup on > advertised listeners > > > > I realize this is a bit heavy but this gives users the ability to pick > and choose. > > I didn't include a setting to mix hostnames and canonical hostnames as > I'm not sure there would be a valid use case. > > > > Alternatively, to have less possible values, we could have 2 parameters : > > > > - dns.lookup.type with values : hostname / canonical.host.name > > - dns.lookup.behaviour : bootstrap.servers, advertised.listeners, both > > > > Thoughts ? > > > > Jonathan Skrzypek > > > > > > -Original Message- > > From: Edoardo Comar [mailto:edoco...@gmail.com] > > Sent: 17 May 2018 23:50 > > To: dev@kafka.apache.org > > Subject: Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS > resolved IP addresses > > > > Hi Jonathan, > > > >> A solution might be to expose to users the choice of using hostname or > canonical host name on both sides. > >> Say having one setting that collapses functionalities from both KIPs > (bootstrap expansion + advertised lookup) > >> and an additional parameter that defines how the resolution is > performed, using getCanonicalHostName() or not. > > > > thanks sounds to me *less* simple than independent config options, sorry. > > > > I would like to say once again that by itself KIP-302 only speeds up > > the client behavior that can happen anyway when the client restarts > > multiple times, > > as every time there is no guarantee that - in presence of multiple A > > DNS records - the same IP is returned. Attempting to use additiona IPs > > if the first fail just makes client recovery faster. > > > > cheers > > Edo > > > > On 17 May 2018 at 12:12, Skrzypek, Jonathan > wrote: > >> Yes, makes sense. > >> You mentioned multiple times you see no overlap and no issue with your > KIP, and that they solve different use cases. > >> > >> Appreciate you have an existing use case that would work, but we need > to make sure this isn't confusing to users and that any combination will > always work, across security protocols. > >> > >> A solution might be to expose to users the choice of using hostname or > canonical host name on both sides. > >> Say having one setting that collapses functionalities from both KIPs > (bootstrap expansion + advertised lookup) and an additional parameter that > defines how the resolution is performed, using getCanonicalHostName() or > not. > >> > >> Maybe that gives less flexibility as users wouldn't be able to decide > to only perform DNS lookup on bootstrap.servers or on advertised listeners. > >> But this would ensure consistency so that a user can decide to use > cnames or not (depending on their certificates and Kerberos principals in > their environment) and it would work. > >> > >> Jonathan Skrzypek > >> > >>
Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
Hi Jonathan, I'm ok with an expandable enum for the config that could be extended in the future. It is marginally better than multiple potentially conflicting config entries. Though as I think the change for KIP-302 is independent from KIP-235 and they do not conflict, when we'll look back at it post 2.0 we may see if it is more valuable to shoehorn its config in an expanded enum or not thanks, Edo On 24 May 2018 at 16:50, Skrzypek, Jonathan <jonathan.skrzy...@gs.com> wrote: > Hi, > > As Rajini suggested in the thread for KIP 235 (attached), we could try to > have an enum that would drive what does the client expands/resolves. > > I suggest a client config called client.dns.lookup with different values > possible : > > - no : no dns lookup > - hostnames.only : perform dns lookup on both bootstrap.servers and > advertised listeners > - canonical.hostnames.only : perform dns lookup on both bootstrap.servers and > advertised listeners > - bootstrap.hostnames.only : perform dns lookup on bootstrap.servers list and > expand it > - bootstrap.canonical.hostnames.only : perform dns lookup on > bootstrap.servers list and expand it > - advertised.listeners.hostnames.only : perform dns lookup on advertised > listeners > - advertised.listeners.canonical.hostnames.only : perform dns lookup on > advertised listeners > > I realize this is a bit heavy but this gives users the ability to pick and > choose. > I didn't include a setting to mix hostnames and canonical hostnames as I'm > not sure there would be a valid use case. > > Alternatively, to have less possible values, we could have 2 parameters : > > - dns.lookup.type with values : hostname / canonical.host.name > - dns.lookup.behaviour : bootstrap.servers, advertised.listeners, both > > Thoughts ? > > Jonathan Skrzypek > > > -Original Message----- > From: Edoardo Comar [mailto:edoco...@gmail.com] > Sent: 17 May 2018 23:50 > To: dev@kafka.apache.org > Subject: Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved > IP addresses > > Hi Jonathan, > >> A solution might be to expose to users the choice of using hostname or >> canonical host name on both sides. >> Say having one setting that collapses functionalities from both KIPs >> (bootstrap expansion + advertised lookup) >> and an additional parameter that defines how the resolution is performed, >> using getCanonicalHostName() or not. > > thanks sounds to me *less* simple than independent config options, sorry. > > I would like to say once again that by itself KIP-302 only speeds up > the client behavior that can happen anyway when the client restarts > multiple times, > as every time there is no guarantee that - in presence of multiple A > DNS records - the same IP is returned. Attempting to use additiona IPs > if the first fail just makes client recovery faster. > > cheers > Edo > > On 17 May 2018 at 12:12, Skrzypek, Jonathan <jonathan.skrzy...@gs.com> wrote: >> Yes, makes sense. >> You mentioned multiple times you see no overlap and no issue with your KIP, >> and that they solve different use cases. >> >> Appreciate you have an existing use case that would work, but we need to >> make sure this isn't confusing to users and that any combination will always >> work, across security protocols. >> >> A solution might be to expose to users the choice of using hostname or >> canonical host name on both sides. >> Say having one setting that collapses functionalities from both KIPs >> (bootstrap expansion + advertised lookup) and an additional parameter that >> defines how the resolution is performed, using getCanonicalHostName() or not. >> >> Maybe that gives less flexibility as users wouldn't be able to decide to >> only perform DNS lookup on bootstrap.servers or on advertised listeners. >> But this would ensure consistency so that a user can decide to use cnames or >> not (depending on their certificates and Kerberos principals in their >> environment) and it would work. >> >> Jonathan Skrzypek >> >> -Original Message- >> From: Edoardo Comar [mailto:edoco...@gmail.com] >> Sent: 16 May 2018 21:59 >> To: dev@kafka.apache.org >> Subject: Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS >> resolved IP addresses >> >> Hi Jonathan, >> I am afraid that may not work for everybody. >> >> It would not work for us. >> With our current DNS, my Kafka clients are perfectly happy to use any IPs - >> DNS has multiple A records for the 'myhostname.mydomain' used for >> bootstrap and advertised listeners. >> The hosts all serve
RE: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
Hi, As Rajini suggested in the thread for KIP 235 (attached), we could try to have an enum that would drive what does the client expands/resolves. I suggest a client config called client.dns.lookup with different values possible : - no : no dns lookup - hostnames.only : perform dns lookup on both bootstrap.servers and advertised listeners - canonical.hostnames.only : perform dns lookup on both bootstrap.servers and advertised listeners - bootstrap.hostnames.only : perform dns lookup on bootstrap.servers list and expand it - bootstrap.canonical.hostnames.only : perform dns lookup on bootstrap.servers list and expand it - advertised.listeners.hostnames.only : perform dns lookup on advertised listeners - advertised.listeners.canonical.hostnames.only : perform dns lookup on advertised listeners I realize this is a bit heavy but this gives users the ability to pick and choose. I didn't include a setting to mix hostnames and canonical hostnames as I'm not sure there would be a valid use case. Alternatively, to have less possible values, we could have 2 parameters : - dns.lookup.type with values : hostname / canonical.host.name - dns.lookup.behaviour : bootstrap.servers, advertised.listeners, both Thoughts ? Jonathan Skrzypek -Original Message- From: Edoardo Comar [mailto:edoco...@gmail.com] Sent: 17 May 2018 23:50 To: dev@kafka.apache.org Subject: Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses Hi Jonathan, > A solution might be to expose to users the choice of using hostname or > canonical host name on both sides. > Say having one setting that collapses functionalities from both KIPs > (bootstrap expansion + advertised lookup) > and an additional parameter that defines how the resolution is performed, > using getCanonicalHostName() or not. thanks sounds to me *less* simple than independent config options, sorry. I would like to say once again that by itself KIP-302 only speeds up the client behavior that can happen anyway when the client restarts multiple times, as every time there is no guarantee that - in presence of multiple A DNS records - the same IP is returned. Attempting to use additiona IPs if the first fail just makes client recovery faster. cheers Edo On 17 May 2018 at 12:12, Skrzypek, Jonathan <jonathan.skrzy...@gs.com> wrote: > Yes, makes sense. > You mentioned multiple times you see no overlap and no issue with your KIP, > and that they solve different use cases. > > Appreciate you have an existing use case that would work, but we need to make > sure this isn't confusing to users and that any combination will always work, > across security protocols. > > A solution might be to expose to users the choice of using hostname or > canonical host name on both sides. > Say having one setting that collapses functionalities from both KIPs > (bootstrap expansion + advertised lookup) and an additional parameter that > defines how the resolution is performed, using getCanonicalHostName() or not. > > Maybe that gives less flexibility as users wouldn't be able to decide to only > perform DNS lookup on bootstrap.servers or on advertised listeners. > But this would ensure consistency so that a user can decide to use cnames or > not (depending on their certificates and Kerberos principals in their > environment) and it would work. > > Jonathan Skrzypek > > -Original Message- > From: Edoardo Comar [mailto:edoco...@gmail.com] > Sent: 16 May 2018 21:59 > To: dev@kafka.apache.org > Subject: Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved > IP addresses > > Hi Jonathan, > I am afraid that may not work for everybody. > > It would not work for us. > With our current DNS, my Kafka clients are perfectly happy to use any IPs - > DNS has multiple A records for the 'myhostname.mydomain' used for > bootstrap and advertised listeners. > The hosts all serve TLS certificates that include > 'myhostname.mydomain' and the clients are happy. > > However, applying getCanonicalHostName to those IPs would return > hostnames that would not match the TLS certificates. > > So once again I believe your solution and ours solve different use cases. > > cheers > Edo > > On 16 May 2018 at 18:29, Skrzypek, Jonathan <jonathan.skrzy...@gs.com> wrote: >> I think there are combinations that will break SASL and SSL auth. >> Could the trick be to have a single parameter that triggers dns resolve both >> for bootstrap and advertised listeners, both using getCanonicalHostName() ? >> >> Jonathan Skrzypek >> >> -----Original Message- >> From: Edoardo Comar [mailto:edoco...@gmail.com] >> Sent: 16 May 2018 17:03 >> To: dev@kafka.apache.org >> Subject: Re: [DISCUSS] KIP-302 - Enable Kafka clients t
Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
Hi Jonathan, > A solution might be to expose to users the choice of using hostname or > canonical host name on both sides. > Say having one setting that collapses functionalities from both KIPs > (bootstrap expansion + advertised lookup) > and an additional parameter that defines how the resolution is performed, > using getCanonicalHostName() or not. thanks sounds to me *less* simple than independent config options, sorry. I would like to say once again that by itself KIP-302 only speeds up the client behavior that can happen anyway when the client restarts multiple times, as every time there is no guarantee that - in presence of multiple A DNS records - the same IP is returned. Attempting to use additiona IPs if the first fail just makes client recovery faster. cheers Edo On 17 May 2018 at 12:12, Skrzypek, Jonathan <jonathan.skrzy...@gs.com> wrote: > Yes, makes sense. > You mentioned multiple times you see no overlap and no issue with your KIP, > and that they solve different use cases. > > Appreciate you have an existing use case that would work, but we need to make > sure this isn't confusing to users and that any combination will always work, > across security protocols. > > A solution might be to expose to users the choice of using hostname or > canonical host name on both sides. > Say having one setting that collapses functionalities from both KIPs > (bootstrap expansion + advertised lookup) and an additional parameter that > defines how the resolution is performed, using getCanonicalHostName() or not. > > Maybe that gives less flexibility as users wouldn't be able to decide to only > perform DNS lookup on bootstrap.servers or on advertised listeners. > But this would ensure consistency so that a user can decide to use cnames or > not (depending on their certificates and Kerberos principals in their > environment) and it would work. > > Jonathan Skrzypek > > -Original Message- > From: Edoardo Comar [mailto:edoco...@gmail.com] > Sent: 16 May 2018 21:59 > To: dev@kafka.apache.org > Subject: Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved > IP addresses > > Hi Jonathan, > I am afraid that may not work for everybody. > > It would not work for us. > With our current DNS, my Kafka clients are perfectly happy to use any IPs - > DNS has multiple A records for the 'myhostname.mydomain' used for > bootstrap and advertised listeners. > The hosts all serve TLS certificates that include > 'myhostname.mydomain' and the clients are happy. > > However, applying getCanonicalHostName to those IPs would return > hostnames that would not match the TLS certificates. > > So once again I believe your solution and ours solve different use cases. > > cheers > Edo > > On 16 May 2018 at 18:29, Skrzypek, Jonathan <jonathan.skrzy...@gs.com> wrote: >> I think there are combinations that will break SASL and SSL auth. >> Could the trick be to have a single parameter that triggers dns resolve both >> for bootstrap and advertised listeners, both using getCanonicalHostName() ? >> >> Jonathan Skrzypek >> >> -----Original Message- >> From: Edoardo Comar [mailto:edoco...@gmail.com] >> Sent: 16 May 2018 17:03 >> To: dev@kafka.apache.org >> Subject: Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS >> resolved IP addresses >> >> Hi Rajini, >> >> In your example KIP-302 would attempt to connect to the first address >> returned, let's say >> >> www.apache.org/195.154.151.36 >> >> then, only if that fails, will in turn try the remaining: >> >> www.apache.org/40.79.78.1 >> www.apache.org/140.211.11.105 >> www.apache.org/2001:bc8:2142:300:0:0:0:0 >> >> You're right to say that we expect certificates served by those >> endpoints to be valid for "www.apache.org" >> >> Without KIP-302, only one would be attempted. >> Which is the first one, that can change every time >> (typically changes on every Java process restart, >> but may change also any time InetAddress.getAllByName it's invoked >> depending on the caching). >> >> The behavioral change that KIP-302 may introduce is that in the example >> above, >> also an IPv6 connection may be attempted after some IPv4 ones. >> >> InetAddress.getAllByName() implementation uses a system property >> "java.net.preferIPv6Addresses" >> to decide which type of address to return first (default is still IPv4 >> in java 10) >> >> We will amend the KIP and PR so that the loop only uses IPs of the >> same type as the first one returned. >> >> A part from the above, KIP
RE: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
Yes, makes sense.
You mentioned multiple times you see no overlap and no issue with your KIP, and
that they solve different use cases.
Appreciate you have an existing use case that would work, but we need to make
sure this isn't confusing to users and that any combination will always work,
across security protocols.
A solution might be to expose to users the choice of using hostname or
canonical host name on both sides.
Say having one setting that collapses functionalities from both KIPs (bootstrap
expansion + advertised lookup) and an additional parameter that defines how the
resolution is performed, using getCanonicalHostName() or not.
Maybe that gives less flexibility as users wouldn't be able to decide to only
perform DNS lookup on bootstrap.servers or on advertised listeners.
But this would ensure consistency so that a user can decide to use cnames or
not (depending on their certificates and Kerberos principals in their
environment) and it would work.
Jonathan Skrzypek
-Original Message-
From: Edoardo Comar [mailto:edoco...@gmail.com]
Sent: 16 May 2018 21:59
To: dev@kafka.apache.org
Subject: Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved
IP addresses
Hi Jonathan,
I am afraid that may not work for everybody.
It would not work for us.
With our current DNS, my Kafka clients are perfectly happy to use any IPs -
DNS has multiple A records for the 'myhostname.mydomain' used for
bootstrap and advertised listeners.
The hosts all serve TLS certificates that include
'myhostname.mydomain' and the clients are happy.
However, applying getCanonicalHostName to those IPs would return
hostnames that would not match the TLS certificates.
So once again I believe your solution and ours solve different use cases.
cheers
Edo
On 16 May 2018 at 18:29, Skrzypek, Jonathan <jonathan.skrzy...@gs.com> wrote:
> I think there are combinations that will break SASL and SSL auth.
> Could the trick be to have a single parameter that triggers dns resolve both
> for bootstrap and advertised listeners, both using getCanonicalHostName() ?
>
> Jonathan Skrzypek
>
> -Original Message-
> From: Edoardo Comar [mailto:edoco...@gmail.com]
> Sent: 16 May 2018 17:03
> To: dev@kafka.apache.org
> Subject: Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved
> IP addresses
>
> Hi Rajini,
>
> In your example KIP-302 would attempt to connect to the first address
> returned, let's say
>
> www.apache.org/195.154.151.36
>
> then, only if that fails, will in turn try the remaining:
>
> www.apache.org/40.79.78.1
> www.apache.org/140.211.11.105
> www.apache.org/2001:bc8:2142:300:0:0:0:0
>
> You're right to say that we expect certificates served by those
> endpoints to be valid for "www.apache.org"
>
> Without KIP-302, only one would be attempted.
> Which is the first one, that can change every time
> (typically changes on every Java process restart,
> but may change also any time InetAddress.getAllByName it's invoked
> depending on the caching).
>
> The behavioral change that KIP-302 may introduce is that in the example above,
> also an IPv6 connection may be attempted after some IPv4 ones.
>
> InetAddress.getAllByName() implementation uses a system property
> "java.net.preferIPv6Addresses"
> to decide which type of address to return first (default is still IPv4
> in java 10)
>
> We will amend the KIP and PR so that the loop only uses IPs of the
> same type as the first one returned.
>
> A part from the above, KIP 302 does not seem to change any existing
> client behaviour, as any one of multiple IP addresses (of a given
> v4/v6 type) can currently be picked.
> We're happy however to keep the looping behavior optional with the
> discussed config property, disabled by default.
>
> As for KIP-235 that may introduce new hostnames in the bootstrap list
> (the current PR rewrites the bootstrap list)
> and we fail to see the conflict with KIP-302, whatever the set of
> configs chosen.
>
> We'd be happy to try understand what we are missing in a KIP call :-)
>
> cheers
> Edo
>
> On 15 May 2018 at 16:58, Rajini Sivaram <rajinisiva...@gmail.com> wrote:
>> Hi Edo,
>>
>> I agree that KIP-235 and KIP-302 address different scenarios. And I agree
>> that each one is not sufficient in itself to address both the scenarios.
>> But I also think that they conflict and hence they need to be looked at
>> together and perhaps use a single config.
>>
>> As an example:
>>
>> If I run:
>>
>> for (InetAddress address : InetAddress.getAllByName("www.apache.org")) {
>> System.out.printf("HostName %s canonicalHostName %s IP %s\n",
>> address.getHostName(), address.getC
Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
Hi Jonathan,
I am afraid that may not work for everybody.
It would not work for us.
With our current DNS, my Kafka clients are perfectly happy to use any IPs -
DNS has multiple A records for the 'myhostname.mydomain' used for
bootstrap and advertised listeners.
The hosts all serve TLS certificates that include
'myhostname.mydomain' and the clients are happy.
However, applying getCanonicalHostName to those IPs would return
hostnames that would not match the TLS certificates.
So once again I believe your solution and ours solve different use cases.
cheers
Edo
On 16 May 2018 at 18:29, Skrzypek, Jonathan <jonathan.skrzy...@gs.com> wrote:
> I think there are combinations that will break SASL and SSL auth.
> Could the trick be to have a single parameter that triggers dns resolve both
> for bootstrap and advertised listeners, both using getCanonicalHostName() ?
>
> Jonathan Skrzypek
>
> -Original Message-
> From: Edoardo Comar [mailto:edoco...@gmail.com]
> Sent: 16 May 2018 17:03
> To: dev@kafka.apache.org
> Subject: Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved
> IP addresses
>
> Hi Rajini,
>
> In your example KIP-302 would attempt to connect to the first address
> returned, let's say
>
> www.apache.org/195.154.151.36
>
> then, only if that fails, will in turn try the remaining:
>
> www.apache.org/40.79.78.1
> www.apache.org/140.211.11.105
> www.apache.org/2001:bc8:2142:300:0:0:0:0
>
> You're right to say that we expect certificates served by those
> endpoints to be valid for "www.apache.org"
>
> Without KIP-302, only one would be attempted.
> Which is the first one, that can change every time
> (typically changes on every Java process restart,
> but may change also any time InetAddress.getAllByName it's invoked
> depending on the caching).
>
> The behavioral change that KIP-302 may introduce is that in the example above,
> also an IPv6 connection may be attempted after some IPv4 ones.
>
> InetAddress.getAllByName() implementation uses a system property
> "java.net.preferIPv6Addresses"
> to decide which type of address to return first (default is still IPv4
> in java 10)
>
> We will amend the KIP and PR so that the loop only uses IPs of the
> same type as the first one returned.
>
> A part from the above, KIP 302 does not seem to change any existing
> client behaviour, as any one of multiple IP addresses (of a given
> v4/v6 type) can currently be picked.
> We're happy however to keep the looping behavior optional with the
> discussed config property, disabled by default.
>
> As for KIP-235 that may introduce new hostnames in the bootstrap list
> (the current PR rewrites the bootstrap list)
> and we fail to see the conflict with KIP-302, whatever the set of
> configs chosen.
>
> We'd be happy to try understand what we are missing in a KIP call :-)
>
> cheers
> Edo
>
> On 15 May 2018 at 16:58, Rajini Sivaram <rajinisiva...@gmail.com> wrote:
>> Hi Edo,
>>
>> I agree that KIP-235 and KIP-302 address different scenarios. And I agree
>> that each one is not sufficient in itself to address both the scenarios.
>> But I also think that they conflict and hence they need to be looked at
>> together and perhaps use a single config.
>>
>> As an example:
>>
>> If I run:
>>
>> for (InetAddress address : InetAddress.getAllByName("www.apache.org")) {
>> System.out.printf("HostName %s canonicalHostName %s IP %s\n",
>> address.getHostName(), address.getCanonicalHostName(),
>> address.getHostAddress());
>> }
>>
>> I get:
>>
>> HostName www.apache.org canonicalHostName tlp-eu-west.apache.org IP
>> 195.154.151.36
>> HostName www.apache.org canonicalHostName 40.79.78.1 IP 40.79.78.1
>> HostName www.apache.org canonicalHostName themis.apache.org IP
>> 140.211.11.105
>> HostName www.apache.org canonicalHostName 2001:bc8:2142:300:0:0:0:0 IP
>> 2001:bc8:2142:300:0:0:0:0
>>
>>
>> If www.apache.org is used as a bootstrap address, KIP-302 would connect to (
>> www.apache.org/195.154.151.36 and www.apache.org/140.211.11.105) while
>> KIP-235 would connect to (tlp-eu-west.apache.org/195.154.151.3. and
>> themis.apache.org/140.211.11.105). This is a significant difference not
>> just for Kerberos, but for any secure environment where hostname is
>> verified to prevent man-in-the-middle attacks. In your case, I presume you
>> would have SSL certificates with the equivalent of www.apache.org on both
>> the load balancers. In Jonathan's case, I presume he has Kerberos
>> principals for the equivalent of tlp-eu-west.apache.org and
>>
RE: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
I think there are combinations that will break SASL and SSL auth.
Could the trick be to have a single parameter that triggers dns resolve both
for bootstrap and advertised listeners, both using getCanonicalHostName() ?
Jonathan Skrzypek
-Original Message-
From: Edoardo Comar [mailto:edoco...@gmail.com]
Sent: 16 May 2018 17:03
To: dev@kafka.apache.org
Subject: Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved
IP addresses
Hi Rajini,
In your example KIP-302 would attempt to connect to the first address
returned, let's say
www.apache.org/195.154.151.36
then, only if that fails, will in turn try the remaining:
www.apache.org/40.79.78.1
www.apache.org/140.211.11.105
www.apache.org/2001:bc8:2142:300:0:0:0:0
You're right to say that we expect certificates served by those
endpoints to be valid for "www.apache.org"
Without KIP-302, only one would be attempted.
Which is the first one, that can change every time
(typically changes on every Java process restart,
but may change also any time InetAddress.getAllByName it's invoked
depending on the caching).
The behavioral change that KIP-302 may introduce is that in the example above,
also an IPv6 connection may be attempted after some IPv4 ones.
InetAddress.getAllByName() implementation uses a system property
"java.net.preferIPv6Addresses"
to decide which type of address to return first (default is still IPv4
in java 10)
We will amend the KIP and PR so that the loop only uses IPs of the
same type as the first one returned.
A part from the above, KIP 302 does not seem to change any existing
client behaviour, as any one of multiple IP addresses (of a given
v4/v6 type) can currently be picked.
We're happy however to keep the looping behavior optional with the
discussed config property, disabled by default.
As for KIP-235 that may introduce new hostnames in the bootstrap list
(the current PR rewrites the bootstrap list)
and we fail to see the conflict with KIP-302, whatever the set of
configs chosen.
We'd be happy to try understand what we are missing in a KIP call :-)
cheers
Edo
On 15 May 2018 at 16:58, Rajini Sivaram <rajinisiva...@gmail.com> wrote:
> Hi Edo,
>
> I agree that KIP-235 and KIP-302 address different scenarios. And I agree
> that each one is not sufficient in itself to address both the scenarios.
> But I also think that they conflict and hence they need to be looked at
> together and perhaps use a single config.
>
> As an example:
>
> If I run:
>
> for (InetAddress address : InetAddress.getAllByName("www.apache.org")) {
> System.out.printf("HostName %s canonicalHostName %s IP %s\n",
> address.getHostName(), address.getCanonicalHostName(),
> address.getHostAddress());
> }
>
> I get:
>
> HostName www.apache.org canonicalHostName tlp-eu-west.apache.org IP
> 195.154.151.36
> HostName www.apache.org canonicalHostName 40.79.78.1 IP 40.79.78.1
> HostName www.apache.org canonicalHostName themis.apache.org IP
> 140.211.11.105
> HostName www.apache.org canonicalHostName 2001:bc8:2142:300:0:0:0:0 IP
> 2001:bc8:2142:300:0:0:0:0
>
>
> If www.apache.org is used as a bootstrap address, KIP-302 would connect to (
> www.apache.org/195.154.151.36 and www.apache.org/140.211.11.105) while
> KIP-235 would connect to (tlp-eu-west.apache.org/195.154.151.3. and
> themis.apache.org/140.211.11.105). This is a significant difference not
> just for Kerberos, but for any secure environment where hostname is
> verified to prevent man-in-the-middle attacks. In your case, I presume you
> would have SSL certificates with the equivalent of www.apache.org on both
> the load balancers. In Jonathan's case, I presume he has Kerberos
> principals for the equivalent of tlp-eu-west.apache.org and
> themis.apache.org. We would want to support both scenarios regardless of
> the security protocol, just need to come up with configuration options that
> don't conflict.
>
>
> On Mon, May 14, 2018 at 5:24 PM, Edoardo Comar <edoco...@gmail.com> wrote:
>
>> Thanks Rajini
>>
>> I still don't see the overlap between the two KIPS
>>
>> KIP-235 allows an expansion of hostnames on the bootstrap list.
>>
>> KIP-302 allows alternative IPs to be used to attempt a connection
>> (either at bootstrap and when processing the MetadataResponse) to a
>> given hostname.
>>
>> A use case would be that of active/passive LB fronting the brokers.
>>
>> Arguably, if Java honored the DNS-set TTL, and the TTL was low and on
>> subsequent requests, the order of IPs returned by the
>> InetAddress.getAllByName() was random, we may not need such an
>> enhancement.
>> In practice, a Java client can get stuck on a "bad" IP forever if it
>> only relies on the first
Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
is KIP could use a single >> > config name with different values instead of two boolean configs: >> > >> > bootstrap.reverse.dns.lookup = true/false >> > enable.all.dns.ips = true/false >> > >> > Not all values of (bootstrap.reverse.dns.lookup, enable.all.dns.ips) seem >> > to make sense. And not all scenarios are handled. Even if we use multiple >> > configs, it seems to me that we may want to name them differently. >> > >> > The possible combinations are: >> > >> > 1) Bootstrap >> > >> > a) No lookup >> > b) Use all DNS entries with host name >> > c) Use all DNS entries with canonical host name >> > >> > 2) Advertised listeners >> > >> > a) No lookup >> > b) Use all DNS entries with host name >> > c) Use all DNS entries with canonical host name >> > >> > The combinations that are enabled by the two boolean configs ( >> > bootstrap.reverse.dns.lookup, enable.all.dns.ips) are: >> > >> >- (false, false) => (1a, 2a) >> >- (true, false) => (1c, 2a) >> >- (false, true) => (1b, 2b) >> >- (true, true) => (??, 2b) >> > >> > It will be good if we can clearly identify which combinations we want to >> > support and the scenarios where they may be useful. Perhaps (1a, 2a), >> (1c, >> > 2a), (1b, 2b) and (1c, 2c) are useful? >> > >> > >> > On Mon, May 14, 2018 at 2:58 PM, Skrzypek, Jonathan < >> > jonathan.skrzy...@gs.com> wrote: >> > >> >> Ah, apologies didn't see there was already a decent amount of discussion >> >> on this in the PR. >> >> >> >> This kind of sounds related to the environment you're running to me. >> >> What is the rationale behind using the advertised listeners to do your >> >> load balancing advertisement rather than a top level alias that has >> >> everything ? >> >> >> >> It sounds like in your case there is a mismatch between >> bootstrap.servers >> >> and advertised.listeners, and you want advertised.listeners to take >> >> precedence and have the client iterate over what is returned by the >> broker. >> >> So the extra parameter doesn't only have to do with DNS but it's also >> >> appending from the broker, maybe the parameter name should reflect this >> ? >> >> >> >> Jonathan Skrzypek >> >> >> >> >> >> -Original Message- >> >> From: Skrzypek, Jonathan [Tech] >> >> Sent: 14 May 2018 14:46 >> >> To: dev@kafka.apache.org >> >> Subject: RE: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS >> >> resolved IP addresses >> >> >> >> Hi, >> >> >> >> I see you noted the similarities with KIP-235. >> >> But KIP-235 might also solve what this KIP is trying to achieve. >> >> >> >> When parsing bootstrap.servers, KIP-235 has the client add all >> underlying >> >> hostnames and IPs. >> >> And this happens before hitting the NetworkClient. >> >> >> >> So to me the client will try every single endpoint behind any >> >> bootstrap.servers record. >> >> >> >> See https://github.com/apache/kafka/pull/4485/commits/24757eb7b0 >> >> 6bcf8c7d7649c85232c52b5d54f0e4#diff-89ef153462e64c250a21bd324ae1a851 >> >> which calls getAllByName like you suggested >> >> >> >> Jonathan Skrzypek >> >> >> >> >> >> -Original Message- >> >> From: Edoardo Comar [mailto:edoco...@gmail.com] >> >> Sent: 14 May 2018 14:17 >> >> To: dev@kafka.apache.org >> >> Subject: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS >> resolved >> >> IP addresses >> >> >> >> Hi all, >> >> >> >> We just opened a KIP to add support for the client to use all IPs >> returned >> >> by DNS for the brokers >> >> >> >> The details are here - >> >> >> >> https://urldefense.proofpoint.com/v2/url?u=https-3A__cwiki.a >> >> pache.org_confluence_display_KAFKA_KIP-2D302-2B-2D-2BEnable- >> >> 2BKafka-2Bclients-2Bto-2Buse-2Ball-2BDNS-2Bresolved-2BIP- >> >> 2Baddresses=DwIBaQ=7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxL >> >> xfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E=EJafF >> >> l1clRyolgtcu2uCc4_cIOJnlxb1r1n-D2Dti4k=C-UZ6KUG7JFiPD_ >> >> CnHczDOVqH9-XC5f_OFkw4BTNrI4= >> >> >> >> The JIRA and provisional PR (where the discussion lead to the creation >> of >> >> this KIP) are : >> >> >> >> https://urldefense.proofpoint.com/v2/url?u=https-3A__issues. >> >> apache.org_jira_browse_KAFKA-2D6863=DwIBaQ=7563p3e2zaQw0 >> >> AB1wrFVgyagb2IE5rTZOYPxLxfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6 >> >> eaCbPOM0NM1EHo-E=EJafFl1clRyolgtcu2uCc4_cIOJnlxb1r1n- >> >> D2Dti4k=3Puqs5iYoPsw6hARQr6gvokdFE-H5USMiNVGOUtNkJI= >> >> >> >> https://urldefense.proofpoint.com/v2/url?u=https-3A__github. >> >> com_apache_kafka_pull_4987=DwIBaQ=7563p3e2zaQw0AB1wrFVgy >> >> agb2IE5rTZOYPxLxfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6eaC >> >> bPOM0NM1EHo-E=EJafFl1clRyolgtcu2uCc4_cIOJnlxb1r1n-D2Dti4k& >> >> s=Hqn5dOgQy4-MHTIJLE49O8bNomry3SoGq9OVoHU-CRA= >> >> >> >> Looking forward to the community's feedback. >> >> It would be amazing to have it voted by May 22nd :-) :-) >> >> >> >> Edoardo & Mickael >> >> >> >> >> >> -- >> "When the people fear their government, there is tyranny; when the >> government fears the people, there is liberty." [Thomas Jefferson] >> -- "When the people fear their government, there is tyranny; when the government fears the people, there is liberty." [Thomas Jefferson]
Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
tch between > bootstrap.servers > >> and advertised.listeners, and you want advertised.listeners to take > >> precedence and have the client iterate over what is returned by the > broker. > >> So the extra parameter doesn't only have to do with DNS but it's also > >> appending from the broker, maybe the parameter name should reflect this > ? > >> > >> Jonathan Skrzypek > >> > >> > >> -Original Message- > >> From: Skrzypek, Jonathan [Tech] > >> Sent: 14 May 2018 14:46 > >> To: dev@kafka.apache.org > >> Subject: RE: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS > >> resolved IP addresses > >> > >> Hi, > >> > >> I see you noted the similarities with KIP-235. > >> But KIP-235 might also solve what this KIP is trying to achieve. > >> > >> When parsing bootstrap.servers, KIP-235 has the client add all > underlying > >> hostnames and IPs. > >> And this happens before hitting the NetworkClient. > >> > >> So to me the client will try every single endpoint behind any > >> bootstrap.servers record. > >> > >> See https://github.com/apache/kafka/pull/4485/commits/24757eb7b0 > >> 6bcf8c7d7649c85232c52b5d54f0e4#diff-89ef153462e64c250a21bd324ae1a851 > >> which calls getAllByName like you suggested > >> > >> Jonathan Skrzypek > >> > >> > >> -Original Message- > >> From: Edoardo Comar [mailto:edoco...@gmail.com] > >> Sent: 14 May 2018 14:17 > >> To: dev@kafka.apache.org > >> Subject: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS > resolved > >> IP addresses > >> > >> Hi all, > >> > >> We just opened a KIP to add support for the client to use all IPs > returned > >> by DNS for the brokers > >> > >> The details are here - > >> > >> https://urldefense.proofpoint.com/v2/url?u=https-3A__cwiki.a > >> pache.org_confluence_display_KAFKA_KIP-2D302-2B-2D-2BEnable- > >> 2BKafka-2Bclients-2Bto-2Buse-2Ball-2BDNS-2Bresolved-2BIP- > >> 2Baddresses=DwIBaQ=7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxL > >> xfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E=EJafF > >> l1clRyolgtcu2uCc4_cIOJnlxb1r1n-D2Dti4k=C-UZ6KUG7JFiPD_ > >> CnHczDOVqH9-XC5f_OFkw4BTNrI4= > >> > >> The JIRA and provisional PR (where the discussion lead to the creation > of > >> this KIP) are : > >> > >> https://urldefense.proofpoint.com/v2/url?u=https-3A__issues. > >> apache.org_jira_browse_KAFKA-2D6863=DwIBaQ=7563p3e2zaQw0 > >> AB1wrFVgyagb2IE5rTZOYPxLxfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6 > >> eaCbPOM0NM1EHo-E=EJafFl1clRyolgtcu2uCc4_cIOJnlxb1r1n- > >> D2Dti4k=3Puqs5iYoPsw6hARQr6gvokdFE-H5USMiNVGOUtNkJI= > >> > >> https://urldefense.proofpoint.com/v2/url?u=https-3A__github. > >> com_apache_kafka_pull_4987=DwIBaQ=7563p3e2zaQw0AB1wrFVgy > >> agb2IE5rTZOYPxLxfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6eaC > >> bPOM0NM1EHo-E=EJafFl1clRyolgtcu2uCc4_cIOJnlxb1r1n-D2Dti4k& > >> s=Hqn5dOgQy4-MHTIJLE49O8bNomry3SoGq9OVoHU-CRA= > >> > >> Looking forward to the community's feedback. > >> It would be amazing to have it voted by May 22nd :-) :-) > >> > >> Edoardo & Mickael > >> > > > > -- > "When the people fear their government, there is tyranny; when the > government fears the people, there is liberty." [Thomas Jefferson] >
Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
Thanks Rajini I still don't see the overlap between the two KIPS KIP-235 allows an expansion of hostnames on the bootstrap list. KIP-302 allows alternative IPs to be used to attempt a connection (either at bootstrap and when processing the MetadataResponse) to a given hostname. A use case would be that of active/passive LB fronting the brokers. Arguably, if Java honored the DNS-set TTL, and the TTL was low and on subsequent requests, the order of IPs returned by the InetAddress.getAllByName() was random, we may not need such an enhancement. In practice, a Java client can get stuck on a "bad" IP forever if it only relies on the first IP returned. HTH, Edo On 14 May 2018 at 16:23, Rajini Sivaram <rajinisiva...@gmail.com> wrote: > Hi Edo, > > Thanks for the KIP. I think it will be good to include a diagram to make it > easier to distinguish this scenario from that of KIP-235 without reading > the PR. > > It may be worth considering if KIP-235 and this KIP could use a single > config name with different values instead of two boolean configs: > > bootstrap.reverse.dns.lookup = true/false > enable.all.dns.ips = true/false > > Not all values of (bootstrap.reverse.dns.lookup, enable.all.dns.ips) seem > to make sense. And not all scenarios are handled. Even if we use multiple > configs, it seems to me that we may want to name them differently. > > The possible combinations are: > > 1) Bootstrap > > a) No lookup > b) Use all DNS entries with host name > c) Use all DNS entries with canonical host name > > 2) Advertised listeners > > a) No lookup > b) Use all DNS entries with host name > c) Use all DNS entries with canonical host name > > The combinations that are enabled by the two boolean configs ( > bootstrap.reverse.dns.lookup, enable.all.dns.ips) are: > >- (false, false) => (1a, 2a) >- (true, false) => (1c, 2a) >- (false, true) => (1b, 2b) >- (true, true) => (??, 2b) > > It will be good if we can clearly identify which combinations we want to > support and the scenarios where they may be useful. Perhaps (1a, 2a), (1c, > 2a), (1b, 2b) and (1c, 2c) are useful? > > > On Mon, May 14, 2018 at 2:58 PM, Skrzypek, Jonathan < > jonathan.skrzy...@gs.com> wrote: > >> Ah, apologies didn't see there was already a decent amount of discussion >> on this in the PR. >> >> This kind of sounds related to the environment you're running to me. >> What is the rationale behind using the advertised listeners to do your >> load balancing advertisement rather than a top level alias that has >> everything ? >> >> It sounds like in your case there is a mismatch between bootstrap.servers >> and advertised.listeners, and you want advertised.listeners to take >> precedence and have the client iterate over what is returned by the broker. >> So the extra parameter doesn't only have to do with DNS but it's also >> appending from the broker, maybe the parameter name should reflect this ? >> >> Jonathan Skrzypek >> >> >> -Original Message- >> From: Skrzypek, Jonathan [Tech] >> Sent: 14 May 2018 14:46 >> To: dev@kafka.apache.org >> Subject: RE: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS >> resolved IP addresses >> >> Hi, >> >> I see you noted the similarities with KIP-235. >> But KIP-235 might also solve what this KIP is trying to achieve. >> >> When parsing bootstrap.servers, KIP-235 has the client add all underlying >> hostnames and IPs. >> And this happens before hitting the NetworkClient. >> >> So to me the client will try every single endpoint behind any >> bootstrap.servers record. >> >> See https://github.com/apache/kafka/pull/4485/commits/24757eb7b0 >> 6bcf8c7d7649c85232c52b5d54f0e4#diff-89ef153462e64c250a21bd324ae1a851 >> which calls getAllByName like you suggested >> >> Jonathan Skrzypek >> >> >> -Original Message- >> From: Edoardo Comar [mailto:edoco...@gmail.com] >> Sent: 14 May 2018 14:17 >> To: dev@kafka.apache.org >> Subject: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved >> IP addresses >> >> Hi all, >> >> We just opened a KIP to add support for the client to use all IPs returned >> by DNS for the brokers >> >> The details are here - >> >> https://urldefense.proofpoint.com/v2/url?u=https-3A__cwiki.a >> pache.org_confluence_display_KAFKA_KIP-2D302-2B-2D-2BEnable- >> 2BKafka-2Bclients-2Bto-2Buse-2Ball-2BDNS-2Bresolved-2BIP- >> 2Baddresses=DwIBaQ=7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxL >> xfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1
Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
Hi Jonathan thanks for your comments > This kind of sounds related to the environment you're running to me. > What is the rationale behind using the advertised listeners to do your load > balancing advertisement rather than a top level alias that has everything ? > > It sounds like in your case there is a mismatch between bootstrap.servers and > advertised.listeners, and you want advertised.listeners to take precedence > and have the client iterate over what is returned by the broker. > So the extra parameter doesn't only have to do with DNS but it's also > appending from the broker, maybe the parameter name should reflect this ? There is no mismatch for us. Our KIP-302 and associated PR allow the network client - both at bootstrap and when using the cluster's metadata response - to connect to the brokers using alternative IPs in case the first one fails. This KIP changes the client behaviour only if the DNS is configured to resolve a single name with multiple valid IP addresses. KIP-235 use case seems targeted to enrich the bootstrap list with more hostnames as long as they all resolve. And I understand it to be Kerberos-motivated. I can't see a similar list expansion being applied to the hostnames returned in a metadata response. KIP-235 doesn't seem to resolve our use case, and KIP-302 doesn't seem to help with yours. I keep seeing as addressing different concerns, the only commonality is ... they have DNS in their titles :-) Edoardo > Jonathan Skrzypek > > > -Original Message- > From: Skrzypek, Jonathan [Tech] > Sent: 14 May 2018 14:46 > To: dev@kafka.apache.org > Subject: RE: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved > IP addresses > > Hi, > > I see you noted the similarities with KIP-235. > But KIP-235 might also solve what this KIP is trying to achieve. > > When parsing bootstrap.servers, KIP-235 has the client add all underlying > hostnames and IPs. > And this happens before hitting the NetworkClient. > > So to me the client will try every single endpoint behind any > bootstrap.servers record. > > See > https://github.com/apache/kafka/pull/4485/commits/24757eb7b06bcf8c7d7649c85232c52b5d54f0e4#diff-89ef153462e64c250a21bd324ae1a851 > which calls getAllByName like you suggested > > Jonathan Skrzypek > > > -Original Message- > From: Edoardo Comar [mailto:edoco...@gmail.com] > Sent: 14 May 2018 14:17 > To: dev@kafka.apache.org > Subject: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP > addresses > > Hi all, > > We just opened a KIP to add support for the client to use all IPs returned > by DNS for the brokers > > The details are here - > > https://urldefense.proofpoint.com/v2/url?u=https-3A__cwiki.apache.org_confluence_display_KAFKA_KIP-2D302-2B-2D-2BEnable-2BKafka-2Bclients-2Bto-2Buse-2Ball-2BDNS-2Bresolved-2BIP-2Baddresses=DwIBaQ=7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxLxfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E=EJafFl1clRyolgtcu2uCc4_cIOJnlxb1r1n-D2Dti4k=C-UZ6KUG7JFiPD_CnHczDOVqH9-XC5f_OFkw4BTNrI4= > > The JIRA and provisional PR (where the discussion lead to the creation of > this KIP) are : > > https://urldefense.proofpoint.com/v2/url?u=https-3A__issues.apache.org_jira_browse_KAFKA-2D6863=DwIBaQ=7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxLxfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E=EJafFl1clRyolgtcu2uCc4_cIOJnlxb1r1n-D2Dti4k=3Puqs5iYoPsw6hARQr6gvokdFE-H5USMiNVGOUtNkJI= > > https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_apache_kafka_pull_4987=DwIBaQ=7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxLxfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E=EJafFl1clRyolgtcu2uCc4_cIOJnlxb1r1n-D2Dti4k=Hqn5dOgQy4-MHTIJLE49O8bNomry3SoGq9OVoHU-CRA= > > Looking forward to the community's feedback. > It would be amazing to have it voted by May 22nd :-) :-) > > Edoardo & Mickael -- "When the people fear their government, there is tyranny; when the government fears the people, there is liberty." [Thomas Jefferson]
Re: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
Hi Edo, Thanks for the KIP. I think it will be good to include a diagram to make it easier to distinguish this scenario from that of KIP-235 without reading the PR. It may be worth considering if KIP-235 and this KIP could use a single config name with different values instead of two boolean configs: bootstrap.reverse.dns.lookup = true/false enable.all.dns.ips = true/false Not all values of (bootstrap.reverse.dns.lookup, enable.all.dns.ips) seem to make sense. And not all scenarios are handled. Even if we use multiple configs, it seems to me that we may want to name them differently. The possible combinations are: 1) Bootstrap a) No lookup b) Use all DNS entries with host name c) Use all DNS entries with canonical host name 2) Advertised listeners a) No lookup b) Use all DNS entries with host name c) Use all DNS entries with canonical host name The combinations that are enabled by the two boolean configs ( bootstrap.reverse.dns.lookup, enable.all.dns.ips) are: - (false, false) => (1a, 2a) - (true, false) => (1c, 2a) - (false, true) => (1b, 2b) - (true, true) => (??, 2b) It will be good if we can clearly identify which combinations we want to support and the scenarios where they may be useful. Perhaps (1a, 2a), (1c, 2a), (1b, 2b) and (1c, 2c) are useful? On Mon, May 14, 2018 at 2:58 PM, Skrzypek, Jonathan < jonathan.skrzy...@gs.com> wrote: > Ah, apologies didn't see there was already a decent amount of discussion > on this in the PR. > > This kind of sounds related to the environment you're running to me. > What is the rationale behind using the advertised listeners to do your > load balancing advertisement rather than a top level alias that has > everything ? > > It sounds like in your case there is a mismatch between bootstrap.servers > and advertised.listeners, and you want advertised.listeners to take > precedence and have the client iterate over what is returned by the broker. > So the extra parameter doesn't only have to do with DNS but it's also > appending from the broker, maybe the parameter name should reflect this ? > > Jonathan Skrzypek > > > -Original Message- > From: Skrzypek, Jonathan [Tech] > Sent: 14 May 2018 14:46 > To: dev@kafka.apache.org > Subject: RE: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS > resolved IP addresses > > Hi, > > I see you noted the similarities with KIP-235. > But KIP-235 might also solve what this KIP is trying to achieve. > > When parsing bootstrap.servers, KIP-235 has the client add all underlying > hostnames and IPs. > And this happens before hitting the NetworkClient. > > So to me the client will try every single endpoint behind any > bootstrap.servers record. > > See https://github.com/apache/kafka/pull/4485/commits/24757eb7b0 > 6bcf8c7d7649c85232c52b5d54f0e4#diff-89ef153462e64c250a21bd324ae1a851 > which calls getAllByName like you suggested > > Jonathan Skrzypek > > > -Original Message- > From: Edoardo Comar [mailto:edoco...@gmail.com] > Sent: 14 May 2018 14:17 > To: dev@kafka.apache.org > Subject: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved > IP addresses > > Hi all, > > We just opened a KIP to add support for the client to use all IPs returned > by DNS for the brokers > > The details are here - > > https://urldefense.proofpoint.com/v2/url?u=https-3A__cwiki.a > pache.org_confluence_display_KAFKA_KIP-2D302-2B-2D-2BEnable- > 2BKafka-2Bclients-2Bto-2Buse-2Ball-2BDNS-2Bresolved-2BIP- > 2Baddresses=DwIBaQ=7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxL > xfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E=EJafF > l1clRyolgtcu2uCc4_cIOJnlxb1r1n-D2Dti4k=C-UZ6KUG7JFiPD_ > CnHczDOVqH9-XC5f_OFkw4BTNrI4= > > The JIRA and provisional PR (where the discussion lead to the creation of > this KIP) are : > > https://urldefense.proofpoint.com/v2/url?u=https-3A__issues. > apache.org_jira_browse_KAFKA-2D6863=DwIBaQ=7563p3e2zaQw0 > AB1wrFVgyagb2IE5rTZOYPxLxfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6 > eaCbPOM0NM1EHo-E=EJafFl1clRyolgtcu2uCc4_cIOJnlxb1r1n- > D2Dti4k=3Puqs5iYoPsw6hARQr6gvokdFE-H5USMiNVGOUtNkJI= > > https://urldefense.proofpoint.com/v2/url?u=https-3A__github. > com_apache_kafka_pull_4987=DwIBaQ=7563p3e2zaQw0AB1wrFVgy > agb2IE5rTZOYPxLxfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6eaC > bPOM0NM1EHo-E=EJafFl1clRyolgtcu2uCc4_cIOJnlxb1r1n-D2Dti4k& > s=Hqn5dOgQy4-MHTIJLE49O8bNomry3SoGq9OVoHU-CRA= > > Looking forward to the community's feedback. > It would be amazing to have it voted by May 22nd :-) :-) > > Edoardo & Mickael >
RE: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
Ah, apologies didn't see there was already a decent amount of discussion on this in the PR. This kind of sounds related to the environment you're running to me. What is the rationale behind using the advertised listeners to do your load balancing advertisement rather than a top level alias that has everything ? It sounds like in your case there is a mismatch between bootstrap.servers and advertised.listeners, and you want advertised.listeners to take precedence and have the client iterate over what is returned by the broker. So the extra parameter doesn't only have to do with DNS but it's also appending from the broker, maybe the parameter name should reflect this ? Jonathan Skrzypek -Original Message- From: Skrzypek, Jonathan [Tech] Sent: 14 May 2018 14:46 To: dev@kafka.apache.org Subject: RE: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses Hi, I see you noted the similarities with KIP-235. But KIP-235 might also solve what this KIP is trying to achieve. When parsing bootstrap.servers, KIP-235 has the client add all underlying hostnames and IPs. And this happens before hitting the NetworkClient. So to me the client will try every single endpoint behind any bootstrap.servers record. See https://github.com/apache/kafka/pull/4485/commits/24757eb7b06bcf8c7d7649c85232c52b5d54f0e4#diff-89ef153462e64c250a21bd324ae1a851 which calls getAllByName like you suggested Jonathan Skrzypek -Original Message- From: Edoardo Comar [mailto:edoco...@gmail.com] Sent: 14 May 2018 14:17 To: dev@kafka.apache.org Subject: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses Hi all, We just opened a KIP to add support for the client to use all IPs returned by DNS for the brokers The details are here - https://urldefense.proofpoint.com/v2/url?u=https-3A__cwiki.apache.org_confluence_display_KAFKA_KIP-2D302-2B-2D-2BEnable-2BKafka-2Bclients-2Bto-2Buse-2Ball-2BDNS-2Bresolved-2BIP-2Baddresses=DwIBaQ=7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxLxfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E=EJafFl1clRyolgtcu2uCc4_cIOJnlxb1r1n-D2Dti4k=C-UZ6KUG7JFiPD_CnHczDOVqH9-XC5f_OFkw4BTNrI4= The JIRA and provisional PR (where the discussion lead to the creation of this KIP) are : https://urldefense.proofpoint.com/v2/url?u=https-3A__issues.apache.org_jira_browse_KAFKA-2D6863=DwIBaQ=7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxLxfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E=EJafFl1clRyolgtcu2uCc4_cIOJnlxb1r1n-D2Dti4k=3Puqs5iYoPsw6hARQr6gvokdFE-H5USMiNVGOUtNkJI= https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_apache_kafka_pull_4987=DwIBaQ=7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxLxfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E=EJafFl1clRyolgtcu2uCc4_cIOJnlxb1r1n-D2Dti4k=Hqn5dOgQy4-MHTIJLE49O8bNomry3SoGq9OVoHU-CRA= Looking forward to the community's feedback. It would be amazing to have it voted by May 22nd :-) :-) Edoardo & Mickael
RE: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses
Hi, I see you noted the similarities with KIP-235. But KIP-235 might also solve what this KIP is trying to achieve. When parsing bootstrap.servers, KIP-235 has the client add all underlying hostnames and IPs. And this happens before hitting the NetworkClient. So to me the client will try every single endpoint behind any bootstrap.servers record. See https://github.com/apache/kafka/pull/4485/commits/24757eb7b06bcf8c7d7649c85232c52b5d54f0e4#diff-89ef153462e64c250a21bd324ae1a851 which calls getAllByName like you suggested Jonathan Skrzypek -Original Message- From: Edoardo Comar [mailto:edoco...@gmail.com] Sent: 14 May 2018 14:17 To: dev@kafka.apache.org Subject: [DISCUSS] KIP-302 - Enable Kafka clients to use all DNS resolved IP addresses Hi all, We just opened a KIP to add support for the client to use all IPs returned by DNS for the brokers The details are here - https://urldefense.proofpoint.com/v2/url?u=https-3A__cwiki.apache.org_confluence_display_KAFKA_KIP-2D302-2B-2D-2BEnable-2BKafka-2Bclients-2Bto-2Buse-2Ball-2BDNS-2Bresolved-2BIP-2Baddresses=DwIBaQ=7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxLxfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E=EJafFl1clRyolgtcu2uCc4_cIOJnlxb1r1n-D2Dti4k=C-UZ6KUG7JFiPD_CnHczDOVqH9-XC5f_OFkw4BTNrI4= The JIRA and provisional PR (where the discussion lead to the creation of this KIP) are : https://urldefense.proofpoint.com/v2/url?u=https-3A__issues.apache.org_jira_browse_KAFKA-2D6863=DwIBaQ=7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxLxfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E=EJafFl1clRyolgtcu2uCc4_cIOJnlxb1r1n-D2Dti4k=3Puqs5iYoPsw6hARQr6gvokdFE-H5USMiNVGOUtNkJI= https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_apache_kafka_pull_4987=DwIBaQ=7563p3e2zaQw0AB1wrFVgyagb2IE5rTZOYPxLxfZlX4=nNmJlu1rR_QFAPdxGlafmDu9_r6eaCbPOM0NM1EHo-E=EJafFl1clRyolgtcu2uCc4_cIOJnlxb1r1n-D2Dti4k=Hqn5dOgQy4-MHTIJLE49O8bNomry3SoGq9OVoHU-CRA= Looking forward to the community's feedback. It would be amazing to have it voted by May 22nd :-) :-) Edoardo & Mickael
