--- Christine Caulfield <ccaulfie@xxxxxxxxxx> wrote: > Ja S wrote: > >>>> If the node doesn't have a local lock on > >>>> the resource then it > >>>> doesn't "know" it and has to ask the directory > >>>> node where it is mastered. > > > >>> Does it mean even if the node owns the master > lock > >>> resource but it doesn't have a local lock > >>> associated with the master lock resource, it > >>> still needs to ask the directory node? > > > > > >> hash tables, hash tables, hash tables ;-) > > > > Sure. Now I see what do you mean "knows". Thanks. > > > > Could you please kindly answer my last question > above? > > The answer is "No" ... because it's in the resource > hash table. > > ... see, I told you it was all hash tables ... > OK. Let's summarise what I have learned from you. If I am wrong, correct me please. A node has a hash table (HT1) which hold the master lock resources and local copies of master lock resources on remote nodes. It also has another hash table (HT2) which holds the content of the lock directory. When an application on a node A requests a lock on a file, DLM feeds the inode number of the file into a hash function and uses the returned hash value to check whether there is a corresponding lock resource record in the hash table HT1. If the record exists, DLM then processes the lock request on the lock resources (either master or local copy). If not, DLM feeds the inode number into another hash function to obtain a node ID (for example node B) which holds the master node information of the target lock resource. DLM then talks with node B and gets the master node ID (for example node C) from the hash table HT2 on node B. Finally, DLM gets the target lock resource from the hash table HT1 on the node C and processes the lock request. Am I right this time, or still missing something (a third hash table?) ? Best, Jas > > Chrissie > > -- > Linux-cluster mailing list > Linux-cluster@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/linux-cluster > -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
