Robert, > I have encountered 5 or so instances in the past several years > where I have attempted to manually restart LDM and received the "The > writer-counter of the product-queue isn't zero..." message, which left > LDM is a stopped state. I always resolved the situation by rebuilding > the queue. In any case, I am somewhat hesitant to restart LDM during > times when I am "pqinsert-ing" large files into the queue (for instance > GRIB files during the model cycles) as I feel that would leave the queue > most vulnerable. That said, I realized recently that the 'ldmadmin check' > (which I run each hour) will induce an automatic restart if it needs > to reconcile the queue (in my case I have a static 4G queue size and > choose to decrease max latency). Getting to my question... are there > any safegaurds built into the 'ldmadmin check' that might prevent the > aforementioned error from occurring if it needs to restart the service? > The last thing I would want is for the LDM service to stop during a > self-induced restart. If there is no guarantee the service will always > restart, is it better to set reconciliation to "do nothing" and manually > reconcile the queue's max latency? Mind you I have never had such a > auto-restart ever fail to restart, but I have had manual restarts result > in the writer-counter error. There are safeguards to ensure that the LDM product-queue doesn't get corrupted. For example, the product-queue library blocks most signals (including SIGTERM) while the queue is being accessed. That being said, there is no guarantee that the LDM code is bug free. I have no qualms having an active reconciliation mode if the product-queue is close to its equilibrium size. The only problems I've seen are when the queue is far too small for the reconciliation algorithm to make a good guess. If the LDM doesn't restart after a reconciliation, then you likely have bigger problems (disk partition full, for example). > Best Regards, > Bob Regards, Steve Emmerson Ticket Details =================== Ticket ID: DCN-100393 Department: Support LDM Priority: Normal Status: Closed
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