perfSONAR User Q&A and Other Discussion

[Casey Russell <>]

Sorry, I should have mentioned.  Following Andrew's hint, I did go back and look, and because this is a toolkit install, the cron job was installed and running, and should have been running periodically to keep the database from growing out of control.  However, reviewing the logfile at /var/log/perfsonar/clean_esmond_db.log reveals that it has been failing with this error for as far back as my logs go each time it tries to run.  

It had fooled me initially because the "Error: timed out" line doesn't appear as the last line in that log file, it's a few lines up from the bottom, so a cursory review of that logfile looks like it ran cleanly.

Sincerely,

Casey Russell

Network Engineer

785-856-9809

2029 Becker Drive, Suite 282
Lawrence, Kansas 66047

On Wed, Aug 9, 2017 at 4:55 PM, Casey Russell <> wrote:

Group,

     I've now shut down the central MA and more than doubled the size of the Disk (root volume).  So it's no longer a issue of raw space.  But still the ps_remove_data.py won't run to completion.  I get somewhere from 10 to 30 minutes in (it seems to vary) and it ends with something like the following:

Deleted 1 rows for metadata_key=189be3bd15fb482a91f2bfb9524c4473, event_type=histogram-rtt, summary_type=aggregation, summary_window=3600

Sending request to delete 1 rows for metadata_key=189be3bd15fb482a91f2bfb9524c4473, event_type=histogram-rtt, summary_type=statistics, summary_window=3600

Deleted 1 rows for metadata_key=189be3bd15fb482a91f2bfb9524c4473, event_type=histogram-rtt, summary_type=statistics, summary_window=3600

Sending request to delete 11 rows for metadata_key=189be3bd15fb482a91f2bfb9524c4473, event_type=histogram-ttl-reverse, summary_type=base, summary_window=0

Deleted 11 rows for metadata_key=189be3bd15fb482a91f2bfb9524c4473, event_type=histogram-ttl-reverse, summary_type=base, summary_window=0

Sending request to delete 11 rows for metadata_key=189be3bd15fb482a91f2bfb9524c4473, event_type=packet-count-lost-bidir, summary_type=base, summary_window=0

Error: Retried 1 times. Last failure was timeout: timed out

None of these:

/var/log/esmond/esmond.log

/var/log/cassandra/cassandra.log

/var/log/httpd/access_log

/var/log/https/error_log

appear to contain anything interesting when the problem occurs.  I've tried running a manual compaction with nodetool in case there were simply so many tombstones hanging out there that it was causing cassandra or Java/Http a problem in processing, didn't make any difference.  Anyone have any thoughts on anything else I should try (adjusting cassandra config file settings, etc.) before I just delete this database and start it fresh?

Sincerely,

Casey Russell

Network Engineer

785-856-9809

2029 Becker Drive, Suite 282
Lawrence, Kansas 66047

On Wed, Jul 26, 2017 at 10:15 AM, Casey Russell <> wrote:

Group,

     I dug myself a hole and I only see a couple of ways out now.  I wasn't watching the database size on my central MA and my disk utilization is now over 90%.  I've tried using the ps_remove_data.py script several times with several different variations on the config script, but it will invariably end some minutes or hours later with a timeout like this:

Sending request to delete 24 rows for metadata_key=1bdb8f32fe9d4194828d134f37fb37b0, event_type=histogram-rtt, summary_type=aggregation, summary_window=3600

Deleted 24 rows for metadata_key=1bdb8f32fe9d4194828d134f37fb37b0, event_type=histogram-rtt, summary_type=aggregation, summary_window=3600

Query error for metadata_key=1bdb8f32fe9d4194828d134f37fb37b0, event_type=histogram-rtt, summary_type=base, summary_window=0, begin_time=0, expire_time=1485529380

Query error for metadata_key=1bdb8f32fe9d4194828d134f37fb37b0, event_type=histogram-rtt, summary_type=statistics, summary_window=0, begin_time=0, expire_time=1485529380

Sending request to delete 24 rows for metadata_key=1bdb8f32fe9d4194828d134f37fb37b0, event_type=histogram-rtt, summary_type=statistics, summary_window=3600

Deleted 24 rows for metadata_key=1bdb8f32fe9d4194828d134f37fb37b0, event_type=histogram-rtt, summary_type=statistics, summary_window=3600

Query error for metadata_key=1bdb8f32fe9d4194828d134f37fb37b0, event_type=histogram-ttl-reverse, summary_type=base, summary_window=0, begin_time=0, expire_time=1469545381

Query error for metadata_key=1bdb8f32fe9d4194828d134f37fb37b0, event_type=packet-count-lost-bidir, summary_type=base, summary_window=0, begin_time=0, expire_time=1469545381

Query error for metadata_key=1bdb8f32fe9d4194828d134f37fb37b0, event_type=packet-duplicates-bidir, summary_type=base, summary_window=0, begin_time=0, expire_time=1469545503

Sending request to delete 24 rows for metadata_key=1bdb8f32fe9d4194828d134f37fb37b0, event_type=packet-loss-rate-bidir, summary_type=aggregation, summary_window=3600

Deleted 24 rows for metadata_key=1bdb8f32fe9d4194828d134f37fb37b0, event_type=packet-loss-rate-bidir, summary_type=aggregation, summary_window=3600

Query error for metadata_key=1bdb8f32fe9d4194828d134f37fb37b0, event_type=packet-loss-rate-bidir, summary_type=base, summary_window=0, begin_time=0, expire_time=1469545505

Query error for metadata_key=1bdb8f32fe9d4194828d134f37fb37b0, event_type=packet-reorders-bidir, summary_type=base, summary_window=0, begin_time=0, expire_time=1469545509

Sending request to delete 6 rows for metadata_key=1be4b626486c46be88776b3530819ce8, event_type=packet-count-lost, summary_type=base, summary_window=0

Deleted 6 rows for metadata_key=1be4b626486c46be88776b3530819ce8, event_type=packet-count-lost, summary_type=base, summary_window=0

Sending request to delete 6 rows for metadata_key=1be4b626486c46be88776b3530819ce8, event_type=packet-count-lost, summary_type=base, summary_window=0

Error: Retried 1 times. Last failure was timeout: timed out

[root@ps-dashboard esmond]# du -h /var/lib/cassandra/data/esmond/

47G     /var/lib/cassandra/data/esmond/raw_data

4.0K    /var/lib/cassandra/data/esmond/stat_aggregations

9.9G    /var/lib/cassandra/data/esmond/rate_aggregations

13G     /var/lib/cassandra/data/esmond/base_rates

69G     /var/lib/cassandra/data/esmond/

[root@ps-dashboard esmond]# df -h

Filesystem            Size  Used Avail Use% Mounted on

/dev/mapper/VolGroup-lv_root

                       95G   82G  8.1G  91% /

tmpfs                 3.9G  4.0K  3.9G   1% /dev/shm

/dev/sda1             477M   99M  353M  22% /boot

At the time of the "timeout" as I watch, the disk reaches 100% utilization.  It appears to me that during the deletion of rows, Cassandra/Esmond uses chunks of disk space to store temporary data, and flushes that data.  During the process the disk utilization varies up and down from 91% to 100% until it finally reaches full and the timeout error occurs.

At the end of the failed attempt, even if I restart cassandra, the disk space utilization is approximately what it was before the failed run.  

So, without enough disk space to finish the ps_remove_data.py script, it would appear to me, I have two options.  Delete all my data and start over with a clean database, or shut the machine down and allocate more space to it (it's a VM, but I can't add the space "hot").

Before I take one of those approaches, does anyone else have other ideas or thoughts?

Sincerely,

Casey Russell

Network Engineer

785-856-9809

2029 Becker Drive, Suite 282
Lawrence, Kansas 66047