Hi Mengxing, Mengxing Liu wrote: > Hi, Alvaro and Kevin. I'm Mengxing. > > This is a “synchronization” email to tell you what I've done and my next > plan. I'm looking forward to your advice.
Welcome! > According to my proposal, I want to prepare the experimental environment > during the community bonding period. > > As this is the first time I discuss with Alvaro, here I will introduce the > environment again. > > My lab have a Lenovo System x3950 X6 machine. > > https://www.lenovo.com/images/products/system-x/pdfs/datasheets/x3950_x6_ds.pdf > > More specifically, there are 8 sockets, each has 15 Intel(R) Xeon(R) CPU > E7-8870 v2 @ 2.30GHz. > > Thus we have 120 cores in total. The storage is a 1 TB SSD, with SAS > interface, 500MB write bandwidth. OK, having a single disk and 120 CPU cores sounds unbalanced. > Because we have too many cores, SSD becomes the bottleneck. In my test, > pgbench can scale to 36 connections. ( 18 KTPS throughput). CPU utilization > is smaller than 30%. > > Therefore: > > 1. Is there anything wrong in my tuning parameters？For example, should I > close "fsync"? Because we don't care recovery here. While it's true that we don't care about recovery, I'm not sure that benchmark results would still be valid with fsync=off. I would try synchronous_commit=off instead, and perhaps also enlarge wal_buffers. What do you have shared_buffers set to? > 2. Can we use just two sockets (30 physical cores) to run database server? > Then the CPU can be the bottleneck so that it shows the problem we try to > solve. Sure -- it's not a Postgres option, but an operating system option: you'd set the "maxcpus" parameter in GRUB when booting Linux. Alternatively, you could use "numactl" to bind the postgres server to a subset of CPUs. (And you could put pgbench on a different CPU set). > > What method of communication will be used among the mentors and with > > Mengxing. > > What method do you prefer? Mailing list is fine. > > Frequency of status updates (must be at least once a week and more often > > is encouraged). > > How about reporting my status once a week? Once a week sounds good to me. > > What steps will be taken next during the community bonding period. > > As I wrote in the proposal, I want to establish the environment and read the > related source code. Do you have any suggestions for me? -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
