How to copy all documents from one solr server to another.
from mysolr import Solr
PACKET_SIZE = 5000
solr_source = Solr('http://server1:8080/solr/')
solr_target = Solr('http://server2:8080/solr/')
# Get the number of documents of the source index
n_documents = solr_source.search(q='*:*', rows=0).total_results
for start in range(0, n_documents, PACKET_SIZE):
resp = solr_source.search(q='*:*', rows=PACKET_SIZE, start=start)
source_docs = resp.documents
solr_target.update(source_docs)