Also, in a cluster where new collections/shards/replicas are continuously added all the time, it would be pretty awkward to start a node (in regular mode), briefly have it become eligible for replica assignment, then invoking a replica placement rule/autoscaling policy for that node to not place replicas on it. Instead, starting a node with a defined role (as a startup param) precludes that brief period of eligibility for replica placement on such a node.
On Wed, Nov 3, 2021 at 5:39 AM Ishan Chattopadhyaya < ichattopadhy...@gmail.com> wrote: > If we were to tell users how to do "scatter gather on an empty node", *how > exactly* would you recommend users have an empty node to begin with? > Wouldn't you say something like "for 8x you can do this (rule based replica > placement) or do that (autoscaling), but for 9x you do this new thing". > Having a node that doesn't have a data role seems like a consistent and an > elegant way for users to invoke such a functionality and also easily relate > to a broad concept, without having to deal with autoscaling frameworks of > the ancient past, medieval past or the future. > > On Wed, Nov 3, 2021 at 5:29 AM Timothy Potter <thelabd...@gmail.com> > wrote: > >> As opposed to what? Looking up the configset for the addressed >> collection and pulling whatever information it needs from cached data. >> I'm sure there are some nuances but I hardly think you need a node >> role framework to deal with determine the unique key field to do >> scatter gather on an empty node when you have easy access to >> collection metadata. >> >> Doesn't seem like a hard thing to overcome to me. >> >> On Tue, Nov 2, 2021 at 5:49 PM Noble Paul <noble.p...@gmail.com> wrote: >> > >> > >> > >> > On Wed, Nov 3, 2021, 10:46 AM Timothy Potter <thelabd...@gmail.com> >> wrote: >> >> >> >> I'm not missing the point of the query coordinator, but I actually >> >> didn't realize that an empty Solr node would forward the top-level >> >> request onward instead of just being the query controller itself? That >> >> actually seems like a bug vs. a feature, IMO any node that receives >> >> the top-level query should just be the coordinator, what stops it? >> > >> > >> > To process a request there should be a core that uses the same >> configset as the requested collection. >> >> >> >> >> >> Anyway, it sounds to me like you guys have your minds made up >> >> regardless of feedback. >> >> >> >> Btw ~ I only mentioned the Zookeeper part b/c it's in your SIP as a >> >> specific role, not sure why you took that as me wanting to discuss the >> >> embedded ZK in your SIP? >> >> >> >> On Tue, Nov 2, 2021 at 5:13 PM Ishan Chattopadhyaya >> >> <ichattopadhy...@gmail.com> wrote: >> >> > >> >> > Hi Tim, >> >> > Here are my responses inline. >> >> > >> >> > On Wed, Nov 3, 2021 at 3:22 AM Timothy Potter <thelabd...@gmail.com> >> wrote: >> >> >> >> >> >> I'm just not convinced this feature is even needed and the SIP is >> not >> >> >> convincing that "There is no proper alternative today." >> >> > >> >> > >> >> > There are no proper alternatives today, just hacks. On 8x, we have >> two different deprecated frameworks to stop nodes from being placed on a >> node (1. rule based replica placement, 2. autoscaling framework). On 9x, we >> have a new autoscaling framework, which I don't even think is fully >> implemented. And, there's definitely no way to have a node act as a query >> coordinator without having data on it. >> >> > >> >> >> >> >> >> >> >> >> 1) Just b/c Elastic and Vespa have a concept of node roles, doesn't >> >> >> mean Solr needs this. >> >> > >> >> > >> >> > Solr needs this. Elastic has such concepts is a coincidence, and >> also means we have an opportunity to catch up with them; they have these >> concepts for a reason. >> >> > >> >> >> >> >> >> Also, some of Elastic's roles overlap with >> >> >> concepts Solr already has in a different form, i.e data_hot sounds >> >> >> like NRT and data_warm sounds a lot like our Pull Replica Type >> >> > >> >> > >> >> > I think that is beyond the scope of this SIP. >> >> > >> >> >> >> >> >> >> >> >> 2) You can achieve the "coordinator" role with auto-scaling rules >> >> >> pre-9.x and with the AffinityPlacementPlugin (heck, it even has a >> node >> >> >> type built in: >> .requestNodeSystemProperty(AffinityPlacementConfig.NODE_TYPE_SYSPROP). >> >> >> Simply build your replica placement rules such that no replicas land >> >> >> on "coordinator" nodes. And you can route queries using node.sysprop >> >> >> already using shards.preference. >> >> > >> >> > >> >> > I think you missed the whole point of the query coordinator. Please >> refer to this https://issues.apache.org/jira/browse/SOLR-15715. >> >> > Let me summarize the main difference between what (I think) you >> refer to and what is proposed in SOLR-15715. >> >> > >> >> > With your suggestion, we'll have a node that doesn't host any >> replicas. And you suggest queries landing on such nodes be routed using >> shards.preference? Well, in such a case, these queries will be >> forwarded/proxied to a random node hosting a replica of the collection and >> that node then acts as the coordinator. This situation is no better than >> sending the query directly to that particular node. >> >> > >> >> > What is proposed in SOLR-15715 is a query aggregation functionality. >> There will be pseudo replicas (aware of the configset) on this coordinator >> node that handle the request themselves, sends shard requests to data >> hosting replicas, collects responses and merges them, and sends back to the >> user. This merge step is usually extremely memory intensive, and it would >> be good to serve these off stateless nodes (that host no data). >> >> > >> >> >> >> >> >> >> >> >> 3) Dedicated overseer role? I thought we were removing the >> overseer?!? >> >> >> Also, we already have the ability to run the overseer on specific >> >> >> nodes w/o a new framework, so this doesn't really convince me we >> need >> >> >> a new framework. >> >> > >> >> > >> >> > There's absolutely no change proposed to the "overseer" role. What >> users need on production clusters are nodes dedicated for overseer >> operations, and for that the current "overseer" role suffices, together >> with some functionality to not place replicas on such nodes. >> >> > >> >> >> >> >> >> >> >> >> 4) We will indeed need to decide which nodes host embedded >> Zookeeper's >> >> >> but I'd argue that solution hasn't been designed entirely and we >> >> >> probably don't need a formal node role framework to determine which >> >> >> nodes host embedded ZKs. Moreover, embedded ZK seems more like a >> small >> >> >> cluster thing and anyone running a large cluster will probably have >> a >> >> >> dedicated ZK ensemble as they do today. The node role thing seems >> like >> >> >> it's intended for large clusters and my gut says few will use >> embedded >> >> >> ZK for large clusters. >> >> > >> >> > >> >> > This SIP is not the right place for this discussion. There's a >> separate SIP for this. >> >> > >> >> >> >> >> >> >> >> >> 5) You can also achieve a lot of "node role" functionality in query >> >> >> routing using the shards.preference parameter. >> >> >> >> >> > >> >> > That doesn't solve the purpose behind >> https://issues.apache.org/jira/browse/SOLR-15715. >> >> > >> >> >> >> >> >> At the very least, the SIP needs to list specific use cases that >> >> >> require this feature that are not achievable with the current >> features >> >> >> before getting bogged down in the impl. details. >> >> > >> >> > >> >> > The coordinator role is the biggest motivation for introducing the >> concept of roles. However, in addition to what is proposed in SOLR-15715, a >> coordinator node can later on also be used as a node for users to run >> streaming expressions on, do bulk indexing on (impl details for this to >> come later, don't want distraction here). >> >> > >> >> >> >> >> >> >> >> >> Tim >> >> >> >> >> >> On Tue, Nov 2, 2021 at 3:20 PM Gus Heck <gus.h...@gmail.com> wrote: >> >> >> > >> >> >> > I think there are things not yet accounted for. Time I spent >> yesterday is biting me today. Pls give a couple days. >> >> >> > >> >> >> > On Tue, Nov 2, 2021 at 11:28 AM Jason Gerlowski < >> gerlowsk...@gmail.com> wrote: >> >> >> >> >> >> >> >> Hey Ishan, >> >> >> >> >> >> >> >> I appreciate you writing up the SIP! Here's some >> notes/questions I >> >> >> >> had as I was reading through your writeup and this mail thread. >> >> >> >> ("----" separators between thoughts, hopefully that helps.) >> >> >> >> >> >> >> >> ---- >> >> >> >> >> >> >> >> I'll add my vote to what Jan, Gus, Ilan, and Houston already >> >> >> >> suggested: roles should default to "all-on". I see the downsides >> >> >> >> you're worried about with that approach (esp. around >> 'overseer'), but >> >> >> >> they may be mitigatable, at least in part. >> >> >> >> >> >> >> >> > [mail thread] User wants this node Solr101 to be a dedicated >> overseer, but for that to happen, he/she would need to restart all the data >> nodes with -Dnode.roles=data >> >> >> >> >> >> >> >> Sure, if roles can only be specified at startup. But that may >> be a >> >> >> >> self-imposed constraint. >> >> >> >> >> >> >> >> An API to change a node's roles would remove the need for a >> restart >> >> >> >> and make it easy for users to affect the semantics they want. >> You >> >> >> >> decided you want a dedicated overseer N nodes into your cluster >> >> >> >> deployment? Deploy node 'N' with the 'overseer', and toggle the >> >> >> >> overseer role off on the remainder. >> >> >> >> >> >> >> >> Now, I understand that you don't want roles to change at >> runtime, but >> >> >> >> I haven't seen you get much into "why", beyond saying "it is very >> >> >> >> risky to have nodes change roles while they are up and >> running." Can >> >> >> >> you expand a bit on the risks you're worried about? If you're >> >> >> >> explicit about them here maybe someone can think of a clever way >> to >> >> >> >> address them? >> >> >> >> >> >> >> >> > Hence, if those nodes are "assumed to have all roles", then >> just by virtue of upgrading to this new version, new capabilities will be >> turned on for the entire cluster, whether or not the user opted for such a >> capability. This is totally undesirable. >> >> >> >> >> >> >> >> Obviously "roles" refer to much bigger chunks of functionality >> than >> >> >> >> usual, so in a sense defaulting roles on is scarier. But in a >> sense >> >> >> >> you're describing something that's an inherent part of software >> >> >> >> releases. Releases expose new features that are typically on by >> >> >> >> default. A new default-on role in 9.1 might hurt a user, but >> there's >> >> >> >> no fundamental difference between that and a change to backups or >> >> >> >> replication or whatever in the same release. >> >> >> >> >> >> >> >> I don't mean to belittle the difference in scope - I get your >> concern. >> >> >> >> But IMO this is something to address with good release notes and >> >> >> >> documentation. Designing for admins who don't do even cursory >> >> >> >> research before an upgrade ties both our hands behind our back >> as a >> >> >> >> project. >> >> >> >> >> >> >> >> ---- >> >> >> >> >> >> >> >> > [SIP] Internal representation in ZK ... Implementation details >> like these can be fleshed out in the PR >> >> >> >> >> >> >> >> IMO this is important enough to flush out as part of the SIP, at >> least >> >> >> >> in broad strokes. It affects backcompat, SolrJ client design, >> etc. >> >> >> >> >> >> >> >> ---- >> >> >> >> >> >> >> >> > [SIP] GET /api/cluster/roles?node=node1 >> >> >> >> >> >> >> >> Woohoo - way to include a v2 API definition! >> >> >> >> >> >> >> >> AFAIR, the v2 API has a /nodes path defined - I wonder whether >> "GET >> >> >> >> /nodes/someNode/roles" wouldn't be a more intuitive endpoint for >> the >> >> >> >> "get the roles this node has" functionality. Though I leave >> that for >> >> >> >> your consideration. >> >> >> >> >> >> >> >> ---- >> >> >> >> >> >> >> >> Looking forward to your responses and seeing the SIP progress! >> It's a >> >> >> >> really cool, promising idea IMO. >> >> >> >> >> >> >> >> Best, >> >> >> >> >> >> >> >> Jason >> >> >> >> >> >> >> >> On Tue, Nov 2, 2021 at 11:21 AM Ishan Chattopadhyaya >> >> >> >> <ichattopadhy...@gmail.com> wrote: >> >> >> >> > >> >> >> >> > Are there any unaddressed outstanding concerns that we should >> hold up the SIP for? >> >> >> >> > >> >> >> >> > On Mon, 1 Nov, 2021, 10:31 pm Ishan Chattopadhyaya, < >> ichattopadhy...@gmail.com> wrote: >> >> >> >> >>> >> >> >> >> >>> >> Agree. However, I disagree with ideas where "query >> analysis" has a role of its own. Where would that lead us to? Separate >> roles for >> >> >> >> >>> >> >> >> >> >>> >> nodes that do "faceting" or "spell correction" etc.? But >> anyway, that is for discussion when we add future roles. This is beyond >> this SIP. >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> > I am not asking you to implement every possible role of >> course :). As a note I know a company that is running an entire separate >> >> >> >> >> > cluster to offload and better serve highlighting on a >> subset of large docs, so YES I think there are people who may want such >> fine grained control. >> >> >> >> >> >> >> >> >> >> Cool, I think we can discuss adding any additional roles (for >> highlighting?) on a case by case basis at a later point. >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> On Mon, Nov 1, 2021 at 10:25 PM Ishan Chattopadhyaya < >> ichattopadhy...@gmail.com> wrote: >> >> >> >> >>> >> >> >> >> >>> > Boiling it down the idea I'm proposing is that roles >> required for back compatibility get explicitly added on startup, if not by >> the user then by the code. This is more flexible than assuming that no role >> means every role, because then every new feature that has a role will end >> up on legacy clusters which are also not back compatible. >> >> >> >> >>> >> >> >> >> >>> +1, I totally agree. I even said so, when I said: "This is >> why I was advocating that 1) we assume the "data" as a default, 2) not >> assume overseer to be implicitly defined (because of the way overseer role >> is written today), 3) not assume any future roles to be true by default." >> >> >> >> >>> >> >> >> >> >>> So, basically, I'm proposing that the "roles required for >> back compatibility" (that should be explicitly added on startup) be just >> the ["data"] role, and not the "overseer" role (due to the way overseer >> role is currently defined, i.e. it is "preferred overseer"). >> >> >> >> >>> >> >> >> >> >>> On Mon, Nov 1, 2021 at 10:19 PM Gus Heck <gus.h...@gmail.com> >> wrote: >> >> >> >> >>>> >> >> >> >> >>>> Very sorry don't mean to sound offended, Frustrated yes >> offended no :)... the most difficult thing about communication is the >> illusion it has occurred :) >> >> >> >> >>>> >> >> >> >> >>>> If you read back just a few emails you'll see where I talk >> about roles being applied on startup. Boiling it down the idea I'm >> proposing is that roles required for back compatibility get explicitly >> added on startup, if not by the user then by the code. This is more >> flexible than assuming that no role means every role, because then every >> new feature that has a role will end up on legacy clusters which are also >> not back compatible. >> >> >> >> >>>> >> >> >> >> >>>> There are points where I said all roles rather than back >> compatibility roles because I was thinking about back compatibility >> specifically, but you can't know that if I don't say that can you :). >> >> >> >> >>>> >> >> >> >> >>>> On Mon, Nov 1, 2021 at 12:39 PM Ishan Chattopadhyaya < >> ichattopadhy...@gmail.com> wrote: >> >> >> >> >>>>> >> >> >> >> >>>>> > If you read more closely, my way can provide full back >> compatibility. To say or imply it doesn't isn't helping. Perhaps you need >> to re-read? >> >> >> >> >>>>> >> >> >> >> >>>>> I understand e-mails are frustrating, and I'm trying my >> best. Please don't be offended, and kindly point me to the exact part you >> want me to re-read. >> >> >> >> >>>>> >> >> >> >> >>>>> On Mon, Nov 1, 2021 at 10:05 PM Gus Heck < >> gus.h...@gmail.com> wrote: >> >> >> >> >>>>>> >> >> >> >> >>>>>> >> >> >> >> >>>>>> >> >> >> >> >>>>>> On Mon, Nov 1, 2021 at 12:22 PM Ishan Chattopadhyaya < >> ichattopadhy...@gmail.com> wrote: >> >> >> >> >>>>>>> >> >> >> >> >>>>>>> > Positive - They denote the existence of a capability >> >> >> >> >>>>>>> >> >> >> >> >>>>>>> Agree, the SIP already reflects this. >> >> >> >> >>>>>>> >> >> >> >> >>>>>>> > Absolute - Absence/Presence binary identification of >> a capability; no implications, no assumptions >> >> >> >> >>>>>>> >> >> >> >> >>>>>>> Disagree, we need backcompat handling on nodes running >> without any roles. There has to be an implicit assumption as to what roles >> are those nodes assumed to have. My proposal is that only the "data" role >> be assumed, but not the "overseer" role. For any future roles >> ("coordinator", "zookeeper" etc.), this decision as to what absence of any >> role implies should be left to the implementation of that future role. >> Documentation should reflect clearly about these implicit assumptions. >> >> >> >> >>>>>>> >> >> >> >> >>>>>> >> >> >> >> >>>>>> If you read more closely, my way can provide full back >> compatibility. To say or imply it doesn't isn't helping. Perhaps you need >> to re-read? >> >> >> >> >>>>>> >> >> >> >> >>>>>>> >> >> >> >> >>>>>>> > Focused - Do one thing per role >> >> >> >> >>>>>>> >> >> >> >> >>>>>>> Agree. However, I disagree with ideas where "query >> analysis" has a role of its own. Where would that lead us to? Separate >> roles for nodes that do "faceting" or "spell correction" etc.? But anyway, >> that is for discussion when we add future roles. This is beyond this SIP. >> >> >> >> >>>>>>> >> >> >> >> >>>>>> >> >> >> >> >>>>>> I am not asking you to implement every possible role of >> course :). As a note I know a company that is running an entire separate >> cluster to offload and better serve highlighting on a subset of large docs, >> so YES I think there are people who may want such fine grained control. >> >> >> >> >>>>>> >> >> >> >> >>>>>>> >> >> >> >> >>>>>>> > Accessible - It should be dead simple to determine >> the members of a role, avoid parsing blobs of json, avoid calculating >> implications, avoid consulting other resources after listing nodes with the >> role >> >> >> >> >>>>>>> >> >> >> >> >>>>>>> Agree. I'm open to any implementation details that make >> it easy. There should be a reasonable API to return these node roles, with >> ability to filter by role or filter by node. >> >> >> >> >>>>>>> >> >> >> >> >>>>>>> > Independent - One role should not require other >> roles to be present >> >> >> >> >>>>>>> >> >> >> >> >>>>>>> Do we need to have this hard and fast requirement >> upfront? There might be situations where this is desirable. I feel we can >> discuss on a case by case basis whenever a future role is added. >> >> >> >> >>>>>>> >> >> >> >> >>>>>>> > Persistent - roles should not be lost across reboot >> >> >> >> >>>>>>> >> >> >> >> >>>>>>> Agree. >> >> >> >> >>>>>>> >> >> >> >> >>>>>>> > Immutable - roles should not change while the node >> is running >> >> >> >> >>>>>>> >> >> >> >> >>>>>>> Agree >> >> >> >> >>>>>>> >> >> >> >> >>>>>>> > Lively - A node with a capability may not be >> presently providing that capability. >> >> >> >> >>>>>>> >> >> >> >> >>>>>>> I don't understand, can you please elaborate? >> >> >> >> >>>>>> >> >> >> >> >>>>>> >> >> >> >> >>>>>> >> >> >> >> >>>>>> Specifically imagine the case where there are 100 nodes: >> >> >> >> >>>>>> 1-100 ==> DATA >> >> >> >> >>>>>> 101-103 ==> OVERSEER >> >> >> >> >>>>>> 104-106 ==> ZOOKEEPER >> >> >> >> >>>>>> >> >> >> >> >>>>>> But you won't have 3 overseers... you'll want only one of >> those to be providing overseer functionality and the other two to be >> capable, but not providing (so that if the current overseer goes down a new >> one can be assigned). >> >> >> >> >>>>>> >> >> >> >> >>>>>> Then you decide you'd ike 5 Zookeepers. You start nodes >> 107-108 with that role, but you probably want to ensure that zookeepers >> require some sort of command for them to actually join the zookeeper >> cluster (i.e. /admin?action=ZKADD&nodes=node107,node18) ... to do that the >> nodes need to be up. But oh look I typoed 108... we want that to fail... >> how? because 18 does not have the capability to become a zookeeper. >> >> >> >> >>>>>> >> >> >> >> >>>>>>> >> >> >> >> >>>>>>> >> >> >> >> >>>>>>> On Mon, Nov 1, 2021 at 9:30 PM Ishan Chattopadhyaya < >> ichattopadhy...@gmail.com> wrote: >> >> >> >> >>>>>>>> >> >> >> >> >>>>>>>> > Ilan: A node not having node.roles defined should be >> assumed to have all roles. Not only data. I don't see a reason to special >> case this one or any role. >> >> >> >> >>>>>>>> > Gus: There should be no "assumptions" Nothing to >> figure out. A node has a role or not. For back compatibility reasons, all >> roles would be assumed on startup if none specified. >> >> >> >> >>>>>>>> > Jan: No role == all roles. Explicit list of roles = >> exactly those roles. >> >> >> >> >>>>>>>> >> >> >> >> >>>>>>>> Problem with this approach is mainly to do with >> backcompat. >> >> >> >> >>>>>>>> >> >> >> >> >>>>>>>> 1. Overseer backcompat: >> >> >> >> >>>>>>>> If we don't make any modifications to how overseer >> works and adopt this approach (as quoted), then imagine this situation: >> >> >> >> >>>>>>>> >> >> >> >> >>>>>>>> Solr1-100: No roles param (assumed to be >> "data,overseer"). >> >> >> >> >>>>>>>> Solr101: -Dnode.roles=overseer (intention: dedicated >> overseer) >> >> >> >> >>>>>>>> >> >> >> >> >>>>>>>> User wants this node Solr101 to be a dedicated >> overseer, but for that to happen, he/she would need to restart all the data >> nodes with -Dnode.roles=data. This will cause unnecessary disruption to >> running clusters where a dedicated overseer is needed. Keep in mind, if a >> user needs a dedicated overseer, he's likely in an emergency situation and >> restarting the whole cluster might not be viable for him/her. >> >> >> >> >>>>>>>> >> >> >> >> >>>>>>>> 2. Future roles might not be compatible with this >> "assumed to have all roles" idea: >> >> >> >> >>>>>>>> Take the proposed "zookeeper" role for example. Today, >> regular nodes are not supposed to have embedded ZK running on them. By >> introducing this artificial limitation ("assumed to have all roles"), we >> constrain adoption of all future roles to necessarily require a full >> cluster restart. >> >> >> >> >>>>>>>> >> >> >> >> >>>>>>>> Keep in mind newer Solr versions can introduce new >> capabilities and roles. Imagine we have a role that is defined in a new >> Solr version (and there's functionality to go with that role), and user >> upgrades to that version. However, his/her nodes all were started with no >> node.roles param. Hence, if those nodes are "assumed to have all roles", >> then just by virtue of upgrading to this new version, new capabilities will >> be turned on for the entire cluster, whether or not the user opted for such >> a capability. This is totally undesirable. >> >> >> >> >>>>>>>> >> >> >> >> >>>>>>>> > Gus: I actually don't want a coordinator to do more >> work, I would prefer small focused roles with names that accurately >> describe their function. In that light, COORDINATOR might be too nebulous. >> How about AGREGATOR role? (what I was thinking of would better be called a >> QUERY_ANALYSIS role) >> >> >> >> >>>>>>>> >> >> >> >> >>>>>>>> If you want to do specific things like query analysis >> or query aggregation or bulk indexing etc, all of those can be done on >> COORDINATOR nodes (as is the case in ElasticSearch). Having tens of of " >> small focused roles" defined as first class concepts would be confusing to >> the user. As a remedy to your situation where you want the coordinator role >> to also do query-analysis for shards, one possible solution is to send such >> a query to a coordinator node with a parameter like >> "coordinator.query_analysis=true", and then the coordinator, instead of >> blindly hitting remote shards, also does some extra work on behalf of the >> shards. >> >> >> >> >>>>>>>> >> >> >> >> >>>>>>>> >> >> >> >> >>>>>>>> On Mon, Nov 1, 2021 at 9:01 PM Ishan Chattopadhyaya < >> ichattopadhy...@gmail.com> wrote: >> >> >> >> >>>>>>>>> >> >> >> >> >>>>>>>>> > If we make collections role-aware for example >> (replicas of that collection can only be >> >> >> >> >>>>>>>>> > placed on nodes with a specific role, in addition to >> the other role based constraints), >> >> >> >> >>>>>>>>> > the set of roles should be user extensible and not >> fixed. >> >> >> >> >>>>>>>>> > If collections are not role aware, the constraints >> introduced by roles apply to all collections >> >> >> >> >>>>>>>>> > equally which might be insufficient if a user needs >> for example a heavily used collection to >> >> >> >> >>>>>>>>> > only be placed on more powerful nodes. >> >> >> >> >>>>>>>>> >> >> >> >> >>>>>>>>> I feel node roles and role-aware collections are >> orthogonal topics. What you describe above can be achieved by the >> autoscaling+replica placement framework where the placement plugins take >> the node roles as one of the inputs. >> >> >> >> >>>>>>>>> >> >> >> >> >>>>>>>>> > It does impact the design from early on: the set of >> roles need to be expandable by a user >> >> >> >> >>>>>>>>> > by creating a collection with new roles for example >> (consumed by placement plugins) and be >> >> >> >> >>>>>>>>> > able to start nodes with new (arbitrary) roles. >> Should such roles follow some naming syntax to >> >> >> >> >>>>>>>>> > differentiate them from built in roles? To be able >> to fail on typos on roles - that otherwise can be >> >> >> >> >>>>>>>>> > crippling and hard to debug. This implies in any >> case that the current design can't assume all >> >> >> >> >>>>>>>>> > roles are known at compile time or define them in a >> Java enum. >> >> >> >> >>>>>>>>> >> >> >> >> >>>>>>>>> I think this should be achieved by something different >> from roles. Something like node labels (user defined) which can then be >> used in a replica placement plugin to assign replicas. I see roles as more >> closely associated with kinds of functionality a node is designated for. >> Therefore, I feel that replica placements and user defined node labels is >> out of scope for this SIP. It can be added later in a separate SIP, without >> being at odds with this proposal. >> >> >> >> >>>>>>>>> >> >> >> >> >>>>>>>>> >> >> >> >> >>>>>>>>> >> >> >> >> >>>>>>>>> >> >> >> >> >>>>>>>>> >> >> >> >> >>>>>>>>> >> >> >> >> >>>>>>>>> On Mon, Nov 1, 2021 at 8:42 PM Jan Høydahl < >> jan....@cominvent.com> wrote: >> >> >> >> >>>>>>>>>> >> >> >> >> >>>>>>>>>> >> >> >> >> >>>>>>>>>> >> >> >> >> >>>>>>>>>> > 1. nov. 2021 kl. 14:46 skrev Ilan Ginzburg < >> ilans...@gmail.com>: >> >> >> >> >>>>>>>>>> > A node not having node.roles defined should be >> assumed to have all roles. Not only data. I don't see a reason to special >> case this one or any role. >> >> >> >> >>>>>>>>>> >> >> >> >> >>>>>>>>>> +1, make it simple and transparent. No role == all >> roles. Explicit list of roles = exactly those roles. >> >> >> >> >>>>>>>>>> >> >> >> >> >>>>>>>>>> > (Gus) See my comment above, but maybe preference is >> something handled as a feature of the role rather than via role designation? >> >> >> >> >>>>>>>>>> >> >> >> >> >>>>>>>>>> Yea, we always need an overseer, so that feature can >> decide to use its list of nodes as a preference if it so chooses. >> >> >> >> >>>>>>>>>> >> >> >> >> >>>>>>>>>> >> >> >> >> >>>>>>>>>> Aside: I think it makes it easier if we always prefix >> Solr env.vars and sys.props with "SOLR_" or "solr.", i.e. >> -Dsolr.node.roles=foo. That way we can get away from having to have >> explicit code in bin/solr, bin/solr.cmd and SolrCLI to manage every single >> property. Instead we can parse all ENVs and Props with the solr prefix in >> our bootstrap code. And we can by convention allow e.g. docker run -e >> SOLR_NODE_ROLES=foo solr:9 and it would be the same ting... >> >> >> >> >>>>>>>>>> >> >> >> >> >>>>>>>>>> Jan >> >> >> >> >>>>>>>>>> >> --------------------------------------------------------------------- >> >> >> >> >>>>>>>>>> To unsubscribe, e-mail: >> dev-unsubscr...@solr.apache.org >> >> >> >> >>>>>>>>>> For additional commands, e-mail: >> dev-h...@solr.apache.org >> >> >> >> >>>>>>>>>> >> >> >> >> >>>>>> >> >> >> >> >>>>>> >> >> >> >> >>>>>> -- >> >> >> >> >>>>>> http://www.needhamsoftware.com (work) >> >> >> >> >>>>>> http://www.the111shift.com (play) >> >> >> >> >>>> >> >> >> >> >>>> >> >> >> >> >>>> >> >> >> >> >>>> -- >> >> >> >> >>>> http://www.needhamsoftware.com (work) >> >> >> >> >>>> http://www.the111shift.com (play) >> >> >> >> >> >> >> >> >> --------------------------------------------------------------------- >> >> >> >> To unsubscribe, e-mail: dev-unsubscr...@solr.apache.org >> >> >> >> For additional commands, e-mail: dev-h...@solr.apache.org >> >> >> >> >> >> >> > >> >> >> > >> >> >> > -- >> >> >> > http://www.needhamsoftware.com (work) >> >> >> > http://www.the111shift.com (play) >> >> >> >> >> >> >> --------------------------------------------------------------------- >> >> >> To unsubscribe, e-mail: dev-unsubscr...@solr.apache.org >> >> >> For additional commands, e-mail: dev-h...@solr.apache.org >> >> >> >> >> >> >> --------------------------------------------------------------------- >> >> To unsubscribe, e-mail: dev-unsubscr...@solr.apache.org >> >> For additional commands, e-mail: dev-h...@solr.apache.org >> >> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: dev-unsubscr...@solr.apache.org >> For additional commands, e-mail: dev-h...@solr.apache.org >> >>
