Hi devs, After implementing ignoring exception some tests failed as we allowed now to pass command again (although it does nothing as the same index is already created by execution before). https://github.com/apache/geode/pull/7195
There is a summary of how it works by now. When we are creating an index on a partitioned region, the locator sends to all members to create an index on all data it contains. The partitioned region is specific as it is normal that you want to index all data which are distributed on all members. That leads to every member will try to create it locally and send index create requests to all members on that site. All members will check if there is an already created index or index creating is in progress and wait for it. In case a remotely originated request comes but there is already created index it will respond with Index and send an acknowledgment to the request sender side. In case it is not created already it will create an index on that member and then respond to the request sender side. This behavior is okay if we are using a small number of the server or using the --member option while creating indexes(which has no sense to use on the partitioned region as already described down in the mail thread). The problem is when we are using a larger num of the servers(8 or more) or just with debugging on. It will slow down the whole process and then can happen that on some of the servers remotely originated create index request comes before locally request. In that case, a remotely originated request will see that there is no index with that name and will create a new one. But the problem happens after that when a local request comes and there is already created index it will think that it is from some execution before and throw IndexNameConflictException. https://github.com/apache/geode/blob/develop/geode-core/src/main/java/org/apache/geode/internal/cache/PartitionedRegion.java#L8377 The create index command will fail(despite of that the index is created on all data, some with local requests ad some with remotely originated requests). There are two problems with this implementation: 1. The user doesn't know that the index is created and will try to create it again but then it will fail on all servers. 2. The cluster config is updated after the command is finished successfully, which is correct as we cannot update the cluster config before anything is done. The user can use indexes despite that command failed, but the problem is that after the restart it has nothing in the cluster config and will not create an index on them. So the question is what to do in this case? How to avoid this issue? Ignore exceptions and fix failing tests expect that a new create index command will pass or disable --member option if partition region is used(or just document it) and don't send a request on other members as the command will send to all members to create it. Or maybe something else? BR, Mario ________________________________ Šalje: Mario Kevo <mario.k...@est.tech> Poslano: 14. prosinca 2021. 14:06 Prima: dev@geode.apache.org <dev@geode.apache.org> Predmet: Odg: Creating index failed Hi Alexandar, The cluster config is updated at the end of the command execution, and only in case, the command is successful. I created PR with Anlikumar's suggestion, but some tests failed. https://github.com/apache/geode/pull/7195 I tried with ignoring exception if it is already created, but in that case, if run again the create index command with the same name and expression it will not fail. BR, Mario ________________________________ Šalje: Alexander Murmann <amurm...@vmware.com> Poslano: 7. prosinca 2021. 18:28 Prima: dev@geode.apache.org <dev@geode.apache.org> Predmet: Re: Creating index failed Hi Mario! I agree with you that the user wanted to index all the data in the region when using a partitioned region. But when the command is not successful, the cluster config is not updated. After the server restart, it will not have indexes as it is not stored in the cluster configuration. Interesting! If I understand you correctly, the initial request to each server succeeds, but later ones will fail because the index is already there. However, the first, successful request should also have updated the cluster config, right?. Am I misunderstanding something? ________________________________ From: Mario Kevo <mario.k...@est.tech> Sent: Tuesday, December 7, 2021 06:36 To: dev@geode.apache.org <dev@geode.apache.org> Subject: Odg: Creating index failed Hi Jason, I agree with you that the user wanted to index all the data in the region when using a partitioned region. But when the command is not successful, the cluster config is not updated. After the server restart, it will not have indexes as it is not stored in the cluster configuration. So there should be some changes, as the index is created on all members but the command is not successful. I'm working on a fix. As soon as possible I will create PR on the already mentioned ticket. BR, Mario ________________________________ Šalje: Jason Huynh <jhu...@vmware.com> Poslano: 6. prosinca 2021. 18:45 Prima: dev@geode.apache.org <dev@geode.apache.org> Predmet: Re: Creating index failed Hi Mario, A lot of the indexing code pre-dates GFSH. The behavior you are seeing is when an index is created on a partition region. When creating an index on a partition region, the idea is that the user wanted to index all the data in the region. So the server will let all other servers know to create an index on the partition region. This is slightly different for an index on a replicated region. That is when the index can be created on a per member basis, which is what I think the -member flag is for. GFSH however defaults to sending the create index message to all members for any index type from what I remember and from what is being described. That is why you’ll see the race condition with indexes created on partitioned regions but the end result being that the index that someone wanted to create is either created or already there. -Jason On 12/6/21, 6:37 AM, "Mario Kevo" <mario.k...@est.tech> wrote: Hi devs, While doing some testing, I found the issue which is already reported there. https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fissues.apache.org%2Fjira%2Fbrowse%2FGEODE-7875&data=04%7C01%7Camurmann%40vmware.com%7C48b13b5a3485492868dd08d9b98efd67%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C1%7C637744846071934875%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=82bEcKRqw8yIP4MCx7hsVKgNprgdWu9Vh%2FNatImH2Vo%3D&reserved=0 If we run the create index command it will create an index locally and send a request to create an index on other members of that region. The problem happened if the remote request comes before the request from the locator, in that case, a request from the locator failed with the following message: Index "index1" already exists. Create failed due to duplicate name. This can be reproduced by running 6 servers with DEBUG log level(due to this system will be slower), creating a partitioned region, and then creating an index. Why does the server send remote requests to other members as they will get a request from the locator to create an index? Also when running the gfsh command to create an index on one member, it will send create index requests to all other members. In that case, what is the purpose of this --member flag? BR, Mario
