Trillian signer is logging excessively

trillian_log_signer is spamming the journal. Here is a sample from the ghost-shrimp primary.

Feb 18 10:22:38 logsrv-02 trillian_log_signer[1038]: I0218 10:22:38.376289    1038 runner.go:148] 3574340866575820521: queue up resignation of mastership 
Feb 18 10:22:38 logsrv-02 trillian_log_signer[1038]: I0218 10:22:38.419464    1038 runner.go:172] 3574340866575820521: deliberately resigning mastership
Feb 18 10:22:38 logsrv-02 trillian_log_signer[1038]: I0218 10:22:38.419525    1038 runner.go:130] 3574340866575820521: Now, I am the master
Feb 18 10:23:03 logsrv-02 trillian_log_signer[1038]: I0218 10:23:03.474992    1038 runner.go:148] 454501516331777276: queue up resignation of mastership
Feb 18 10:23:03 logsrv-02 trillian_log_signer[1038]: I0218 10:23:03.565729    1038 runner.go:172] 454501516331777276: deliberately resigning mastership
Feb 18 10:23:03 logsrv-02 trillian_log_signer[1038]: I0218 10:23:03.565829    1038 runner.go:130] 454501516331777276: Now, I am the master
Feb 18 10:23:12 logsrv-02 trillian_log_signer[1038]: I0218 10:23:12.934982    1038 runner.go:148] 1595563996642183944: queue up resignation of mastership
Feb 18 10:23:13 logsrv-02 trillian_log_signer[1038]: I0218 10:23:13.019985    1038 runner.go:172] 1595563996642183944: deliberately resigning mastership
Feb 18 10:23:13 logsrv-02 trillian_log_signer[1038]: I0218 10:23:13.020116    1038 runner.go:130] 1595563996642183944: Now, I am the master
Feb 18 10:23:17 logsrv-02 trillian_log_signer[1038]: I0218 10:23:17.497928    1038 runner.go:148] 1601398788111984518: queue up resignation of mastership
Feb 18 10:23:17 logsrv-02 trillian_log_signer[1038]: I0218 10:23:17.549692    1038 runner.go:172] 1601398788111984518: deliberately resigning mastership
Feb 18 10:23:17 logsrv-02 trillian_log_signer[1038]: I0218 10:23:17.549761    1038 runner.go:130] 1601398788111984518: Now, I am the master
Feb 18 10:23:34 logsrv-02 trillian_log_signer[1038]: I0218 10:23:34.060741    1038 runner.go:148] 5537291957187304042: queue up resignation of mastership
Feb 18 10:23:34 logsrv-02 trillian_log_signer[1038]: I0218 10:23:34.148068    1038 runner.go:172] 5537291957187304042: deliberately resigning mastership
Feb 18 10:23:34 logsrv-02 trillian_log_signer[1038]: I0218 10:23:34.148171    1038 runner.go:130] 5537291957187304042: Now, I am the master
Feb 18 10:23:42 logsrv-02 trillian_log_signer[1038]: I0218 10:23:42.848125    1038 runner.go:148] 8538994558506365671: queue up resignation of mastership
Feb 18 10:23:42 logsrv-02 trillian_log_signer[1038]: I0218 10:23:42.900676    1038 runner.go:172] 8538994558506365671: deliberately resigning mastership
Feb 18 10:23:42 logsrv-02 trillian_log_signer[1038]: I0218 10:23:42.900737    1038 runner.go:130] 8538994558506365671: Now, I am the master
Feb 18 10:24:09 logsrv-02 trillian_log_signer[1038]: I0218 10:24:09.500162    1038 runner.go:148] 4862855759252212211: queue up resignation of mastership
Feb 18 10:24:09 logsrv-02 trillian_log_signer[1038]: I0218 10:24:09.554432    1038 runner.go:172] 4862855759252212211: deliberately resigning mastership
Feb 18 10:24:09 logsrv-02 trillian_log_signer[1038]: I0218 10:24:09.554519    1038 runner.go:130] 4862855759252212211: Now, I am the master
Feb 18 10:24:10 logsrv-02 trillian_log_signer[1038]: I0218 10:24:10.650241    1038 runner.go:148] 7249559290824594003: queue up resignation of mastership
Feb 18 10:24:10 logsrv-02 trillian_log_signer[1038]: I0218 10:24:10.664711    1038 runner.go:172] 7249559290824594003: deliberately resigning mastership
Feb 18 10:24:10 logsrv-02 trillian_log_signer[1038]: I0218 10:24:10.664773    1038 runner.go:130] 7249559290824594003: Now, I am the master
Feb 18 10:24:33 logsrv-02 trillian_log_signer[1038]: I0218 10:24:33.468700    1038 runner.go:148] 8063077113757874269: queue up resignation of mastership
Feb 18 10:24:33 logsrv-02 trillian_log_signer[1038]: I0218 10:24:33.494688    1038 runner.go:172] 8063077113757874269: deliberately resigning mastership
Feb 18 10:24:33 logsrv-02 trillian_log_signer[1038]: I0218 10:24:33.494756    1038 runner.go:130] 8063077113757874269: Now, I am the master
Feb 18 10:24:42 logsrv-02 trillian_log_signer[1038]: I0218 10:24:42.388585    1038 runner.go:148] 454501516331777276: queue up resignation of mastership
Feb 18 10:24:42 logsrv-02 trillian_log_signer[1038]: I0218 10:24:42.447912    1038 runner.go:172] 454501516331777276: deliberately resigning mastership
Feb 18 10:24:42 logsrv-02 trillian_log_signer[1038]: I0218 10:24:42.448000    1038 runner.go:130] 454501516331777276: Now, I am the master

This is how trillian_log_signer is being started:

ExecStart=/var/sigsum/sigsum/go/bin/trillian_log_signer \
    --force_master \
    --rpc_endpoint=localhost:6961 \
    --http_endpoint=localhost:6964 \
    --num_sequencers 1 \
    --sequencer_interval 100ms \
    --batch_size 1000  \
    --mysql_uri 'sigsum:**REDACTED**@tcp(127.0.0.1:3306)/ghost_shrimp'

(The password exposure issue is being tracked in sigsum/admin/ansible#27.)

Are these harmless debug messages/informational messages? Can they be disabled by setting log level?