hourly cpu load average spike for the past seven days

hi guys,

i opened a support ticket last wednesday but have yet to get a reply from DO support team.

i have tried a few suggestions on various websites (like netdata and cron jobs) but cant figure out why our droplet’s cpu load average spikes almost every hour.

below is the ticket i submitted. any idea would be appreciated.

thank you so much.

br, tom

[Ticket #3518872] WordPress website ERROR ESTABLISHING A DATABASE CONNECTION occasionally Friday, June 26, 2020 3:32 PM hi there,

its been more than two days but no one replies to our ticket!!!

br, tom Thursday, June 25, 2020 4:32 PM hi there,

i have installed htop and captured the screen as attached when the websites were down. however, i aint sure if that is the exact moment when the sites were down because they had been down just momentarily perhaps less than 5 seconds this time.

any idea by looking at the screenshot?

br, tom Thursday, June 25, 2020 3:57 PM hi there, below is the last 40 lines of the MySQL error log. it doesn’t look like MySQL had crashed, does it?

2020-06-25T15:25:05.251492Z 0 [Note] InnoDB: Uses event mutexes 2020-06-25T15:25:05.251505Z 0 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier 2020-06-25T15:25:05.251514Z 0 [Note] InnoDB: Compressed tables use zlib 1.2.8 2020-06-25T15:25:05.251538Z 0 [Note] InnoDB: Using Linux native AIO 2020-06-25T15:25:05.253700Z 0 [Note] InnoDB: Number of pools: 1 2020-06-25T15:25:05.256435Z 0 [Note] InnoDB: Using CPU crc32 instructions 2020-06-25T15:25:05.259595Z 0 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances = 1, chunk size = 128M 2020-06-25T15:25:05.273615Z 0 [Note] InnoDB: Completed initialization of buffer pool 2020-06-25T15:25:05.277386Z 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority(). 2020-06-25T15:25:05.293193Z 0 [Note] InnoDB: Highest supported file format is Barracuda. 2020-06-25T15:25:05.306123Z 0 [Note] InnoDB: Log scan progressed past the checkpoint lsn 88745418477 2020-06-25T15:25:05.306205Z 0 [Note] InnoDB: Doing recovery: scanned up to log sequence number 88745424052 2020-06-25T15:25:05.308820Z 0 [Note] InnoDB: Database was not shutdown normally! 2020-06-25T15:25:05.308839Z 0 [Note] InnoDB: Starting crash recovery. 2020-06-25T15:25:05.357119Z 0 [Note] InnoDB: Starting an apply batch of log records to the database… InnoDB: Progress in percent: 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 2020-06-25T15:25:05.865445Z 0 [Note] InnoDB: Apply batch completed 2020-06-25T15:25:07.276187Z 0 [Note] InnoDB: Removed temporary tablespace data file: “ibtmp1” 2020-06-25T15:25:07.276221Z 0 [Note] InnoDB: Creating shared tablespace for temporary tables 2020-06-25T15:25:07.276287Z 0 [Note] InnoDB: Setting file ‘./ibtmp1’ size to 12 MB. Physically writing the file full; Please wait … 2020-06-25T15:25:07.299165Z 0 [Note] InnoDB: File ‘./ibtmp1’ size is now 12 MB. 2020-06-25T15:25:07.300482Z 0 [Note] InnoDB: 96 redo rollback segment(s) found. 96 redo rollback segment(s) are active. 2020-06-25T15:25:07.300500Z 0 [Note] InnoDB: 32 non-redo rollback segment(s) are active. 2020-06-25T15:25:07.300997Z 0 [Note] InnoDB: Waiting for purge to start 2020-06-25T15:25:07.351460Z 0 [Note] InnoDB: 5.7.30 started; log sequence number 88745424052 2020-06-25T15:25:07.351886Z 0 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool 2020-06-25T15:25:07.353935Z 0 [Note] Plugin ‘FEDERATED’ is disabled. 2020-06-25T15:25:07.375810Z 0 [Note] Found ca.pem, server-cert.pem and server-key.pem in data directory. Trying to enable SSL support using them. 2020-06-25T15:25:07.375843Z 0 [Note] Skipping generation of SSL certificates as certificate files are present in data directory. 2020-06-25T15:25:07.379191Z 0 [Warning] CA certificate ca.pem is self signed. 2020-06-25T15:25:07.379246Z 0 [Note] Skipping generation of RSA key pair as key files are present in data directory. 2020-06-25T15:25:07.379998Z 0 [Note] Server hostname (bind-address): ‘127.0.0.1’; port: 3306 2020-06-25T15:25:07.380021Z 0 [Note] - ‘127.0.0.1’ resolves to ‘127.0.0.1’; 2020-06-25T15:25:07.380062Z 0 [Note] Server socket created on IP: ‘127.0.0.1’. 2020-06-25T15:25:07.427486Z 0 [Note] Event Scheduler: Loaded 0 events 2020-06-25T15:25:07.427839Z 0 [Note] /usr/sbin/mysqld: ready for connections. Version: ‘5.7.30-0ubuntu0.16.04.1’ socket: ‘/var/run/mysqld/mysqld.sock’ port: 3306 (Ubuntu) 2020-06-25T15:25:07.500492Z 0 [Note] InnoDB: Buffer pool(s) load completed at 200625 15:25:07 2020-06-25T15:25:08.034358Z 2 [Note] Access denied for user ‘root’@‘localhost’ (using password: NO) 2020-06-25T15:31:51.064814Z 81 [Note] Access denied for user ‘root’@‘localhost’ (using password: NO) sonnyy@azinity.com Thursday, June 25, 2020 3:40 PM hi there,

attached is the latest 6-hour graph which shows that the load average spikes periodically approximately every hour. the same goes for disk i/o. any idea?

br, tom Wednesday, June 24, 2020 6:12 PM hi there,

attached is the 14-day graph which shows that the load and disk i/o data started to go haywire starting jun 20. any idea?

look forward to hearing from you as soon as you can. thank you so much!

br, tom Wednesday, June 24, 2020 5:27 PM hi there,

one quick question.

is there a limitation on the maximum number of concurrent connections to a database?

thanks in advance.

br, tom Wednesday, June 24, 2020 11:49 AM hi there,

i forgot to tell you that we have over 40 websites sitting on this droplet. when it’s down, all the websites are down with the same error message but most of the time for just less than 15 seconds.

any idea? br, tom Wednesday, June 24, 2020 11:17 AM Hi there,

Starting last week, we occasionally get the error message “ERROR ESTABLISHING A DATABASE CONNECTION” on both the website and the admin panel. We have checked the wp-config.php and the database and have not found any issue. Any idea why?

We have checked the droplet performance graphs and found something that demands our attention. There were a few spikes in the bandwidth as well as load average and disk i/o. Any idea?

Look forward to hearing from you shortly. Thanks a lot.

BR, Tom